diff --git a/src/org/olap4j/driver/xmla/cache/XmlaOlap4jCache.java b/src/org/olap4j/driver/xmla/cache/XmlaOlap4jCache.java
index d94d3be..b1e32ea 100644
--- a/src/org/olap4j/driver/xmla/cache/XmlaOlap4jCache.java
+++ b/src/org/olap4j/driver/xmla/cache/XmlaOlap4jCache.java
@@ -12,6 +12,8 @@
 import java.net.URL;
 import java.util.Map;
 
+import org.olap4j.OlapException;
+
 /**
  * XMLA driver cache. Implementations will have to declare those methods.
  *
@@ -37,9 +39,9 @@ public interface XmlaOlap4jCache {
      * @param url The URL where the SOAP message was sent.
      * @param request The SOAP complete message.
      *
-     * @throws XmlaOlap4jInvalidStateException when
-     * operations to the cache are performed but it hasn't been initialized.
-     * Make sure you call the setParameters method.
+     * @throws OlapException when operations to the cache are
+     * performed but it hasn't been initialized. Make sure you
+     * call the setParameters(Map, Map) method.
      *
      * @return The SOAP response, null if there are no corresponding
      * response in the cache.
@@ -48,7 +50,7 @@ public byte[] get(
         String id,
         URL url,
         byte[] request)
-        throws XmlaOlap4jInvalidStateException;
+        throws OlapException;
 
     /**
      * Adds a SOAP response to the cache. It has to be relative to the
@@ -60,16 +62,16 @@ public byte[] get(
      * response.
      * @param response The response to cache.
      *
-     * @throws XmlaOlap4jInvalidStateException when
-     * operations to the cache are performed but it hasn't been initialized.
-     * Make sure you call the setParameters method.
+     * @throws OlapException when operations to the cache are
+     * performed but it hasn't been initialized. Make sure you
+     * call the setParameters(Map, Map) method.
      */
     public void put(
         String id,
         URL url,
         byte[] request,
         byte[] response)
-        throws XmlaOlap4jInvalidStateException;
+        throws OlapException;
 
     /**
      * Tells the cache to flush all cached entries.
@@ -82,9 +84,9 @@ public void put(
      * <p>The XMLA driver takes cache properties as
      * "<code>Cache.[property name]=[value]</code>" in its JDBC url. All those
      * properties should be striped of their "<code>Cache.</code>" prefix and
-     * sent to this method as the properties parameter.
+     * sent to this method as the props parameter.
      *
-     * <p>Also, the complete config map of the current connection
+     * <p>Also, the complete  map of the current connection
      * should be passed as the config parameter.
      *
      * @param config The complete configuration parameters which were used to
diff --git a/src/org/olap4j/driver/xmla/cache/XmlaOlap4jInvalidStateException.java b/src/org/olap4j/driver/xmla/cache/XmlaOlap4jInvalidStateException.java
index 83921d3..80d7d61 100644
--- a/src/org/olap4j/driver/xmla/cache/XmlaOlap4jInvalidStateException.java
+++ b/src/org/olap4j/driver/xmla/cache/XmlaOlap4jInvalidStateException.java
@@ -9,18 +9,16 @@
 */
 package org.olap4j.driver.xmla.cache;
 
+import org.olap4j.OlapException;
+
 /**
  * <p>Internal exception which gets thrown when operations to the cache
  * are performed but it hasn't been initialized.
  *
- * <p>It extends RuntimeException so it cannot be catched by the
- * regular catch(Exception) mechanism. Those exceptions should get right
- * to the system level since it's a programming error.
- *
  * @author Luc Boudreau
  * @version $Id$
  */
-class XmlaOlap4jInvalidStateException extends RuntimeException {
+public class XmlaOlap4jInvalidStateException extends OlapException {
     private static final long serialVersionUID = 7265273715459263740L;
 }
 
diff --git a/src/org/olap4j/driver/xmla/proxy/XmlaOlap4jAbstractHttpProxy.java b/src/org/olap4j/driver/xmla/proxy/XmlaOlap4jAbstractHttpProxy.java
index 079a384..d4f2513 100644
--- a/src/org/olap4j/driver/xmla/proxy/XmlaOlap4jAbstractHttpProxy.java
+++ b/src/org/olap4j/driver/xmla/proxy/XmlaOlap4jAbstractHttpProxy.java
@@ -9,14 +9,14 @@
 */
 package org.olap4j.driver.xmla.proxy;
 
-import java.io.*;
-import java.net.*;
-import java.util.*;
-import java.util.concurrent.*;
+import java.net.URL;
+import java.net.URLConnection;
+import java.util.Map;
+import java.util.concurrent.Future;
 
 import org.olap4j.OlapException;
-import org.olap4j.driver.xmla.XmlaOlap4jDriver;
 import org.olap4j.driver.xmla.XmlaHelper;
+import org.olap4j.driver.xmla.XmlaOlap4jDriver;
 import org.olap4j.driver.xmla.cache.XmlaOlap4jCache;
 
 /**
@@ -159,7 +159,7 @@ public byte[] get(URL url, String request) throws XmlaOlap4jProxyException {
             if (response != null) {
                 return response;
             }
-        } catch (IOException e) {
+        } catch (Exception e) {
             throw new XmlaOlap4jProxyException(
                 "An exception was encountered while browsing the proxy cache.",
                 e);
@@ -176,7 +176,7 @@ public byte[] get(URL url, String request) throws XmlaOlap4jProxyException {
                 response);
             // Returns result
             return response;
-        } catch (IOException e) {
+        } catch (Exception e) {
             throw new XmlaOlap4jProxyException(
                 "An exception was encountered while saving a response in the proxy cache.",
                 e);
@@ -194,7 +194,9 @@ public byte[] get(URL url, String request) throws XmlaOlap4jProxyException {
      * @return either a response in a byte array or null
      * if the response is not in cache
      */
-    private byte[] getFromCache(final URL url, final byte[] request) {
+    private byte[] getFromCache(final URL url, final byte[] request)
+            throws OlapException
+    {
         return (this.cache != null)
             ? this.cache.get(this.cacheId, url, request)
             : null;
@@ -207,7 +209,9 @@ private byte[] getFromCache(final URL url, final byte[] request) {
      * @param request The SOAP request to cache
      * @param response The SOAP response to cache
      */
-    private void addToCache(URL url, byte[] request, byte[] response) {
+    private void addToCache(URL url, byte[] request, byte[] response)
+            throws OlapException
+    {
         if (this.cache != null) {
             this.cache.put(this.cacheId, url, request, response);
         }