diff --git a/dom/public/nsIScriptContext.h b/dom/public/nsIScriptContext.h
index 5d010b3f947b..e2206e06f0da 100644
--- a/dom/public/nsIScriptContext.h
+++ b/dom/public/nsIScriptContext.h
@@ -140,6 +140,15 @@ public:
    * @return NS_OK if the method is successful
    */
   NS_IMETHOD GetSecurityManager(nsIScriptSecurityManager** aInstancePtr) = 0;
+
+  /**
+   * Inform the context that a script was evaluated.
+   * A GC may be done if "necessary."
+   * This call is necessary if script evaluation is done
+   * without using the EvaluateScript method.
+   * @return NS_OK if the method is successful
+   */
+  NS_IMETHOD ScriptEvaluated(void) = 0;
 };
 
 /**
diff --git a/dom/src/base/nsGlobalWindow.cpp b/dom/src/base/nsGlobalWindow.cpp
index 37f4debd323d..9e6c736cb8c8 100644
--- a/dom/src/base/nsGlobalWindow.cpp
+++ b/dom/src/base/nsGlobalWindow.cpp
@@ -1100,6 +1100,15 @@ GlobalWindowImpl::RunTimeout(nsTimeoutImpl *aTimeout)
 
       if (timeout->expr) {
         /* Evaluate the timeout expression. */
+#if 0
+        // V says it would be nice if we could have a chokepoint
+        // for calling scripts instead of making a bunch of
+        // ScriptEvaluated() calls to clean things up. MMP
+        PRBool isundefined;
+        mContext->EvaluateString(nsAutoString(timeout->expr),
+                                 timeout->filename,
+                                 timeout->lineno, nsAutoString(""), &isundefined);
+#endif
         JS_EvaluateScript(cx, (JSObject *)mScriptObject,
                           timeout->expr, 
                           PL_strlen(timeout->expr),
@@ -1121,6 +1130,8 @@ GlobalWindowImpl::RunTimeout(nsTimeoutImpl *aTimeout)
                              timeout->argc + 1, timeout->argv, &result);
       }
 
+      mContext->ScriptEvaluated();
+
       mRunningTimeout = nsnull;
 
       /* If we have a regular interval timer, we re-fire the
diff --git a/dom/src/base/nsJSEnvironment.cpp b/dom/src/base/nsJSEnvironment.cpp
index 33259685a794..04955d404712 100644
--- a/dom/src/base/nsJSEnvironment.cpp
+++ b/dom/src/base/nsJSEnvironment.cpp
@@ -67,6 +67,7 @@ nsJSContext::nsJSContext(JSRuntime *aRuntime)
   JS_SetContextPrivate(mContext, (void *)this);
   mNameSpaceManager = nsnull;
   mIsInitialized = PR_FALSE;
+  mNumEvaluations = 0;
 }
 
 nsJSContext::~nsJSContext()
@@ -104,6 +105,8 @@ nsJSContext::EvaluateString(const nsString& aScript,
     aRetValue.Truncate();
   }
 
+  ScriptEvaluated();
+
   return ret;
 }
 
@@ -268,6 +271,19 @@ nsJSContext::GC()
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsJSContext::ScriptEvaluated(void)
+{
+  mNumEvaluations++;
+
+  if (mNumEvaluations > 20) {
+    mNumEvaluations = 0;
+    GC();
+  }
+
+  return NS_OK;
+}
+
 NS_IMETHODIMP 
 nsJSContext::GetNameSpaceManager(nsIScriptNameSpaceManager** aInstancePtr)
 {
diff --git a/dom/src/base/nsJSEnvironment.h b/dom/src/base/nsJSEnvironment.h
index 84a872e8a7d0..8155e7586302 100644
--- a/dom/src/base/nsJSEnvironment.h
+++ b/dom/src/base/nsJSEnvironment.h
@@ -29,6 +29,7 @@ private:
   JSContext *mContext;
   nsIScriptNameSpaceManager* mNameSpaceManager;
   PRBool mIsInitialized;
+  PRUint32 mNumEvaluations;
 
 public:
   nsJSContext(JSRuntime *aRuntime);
@@ -53,6 +54,8 @@ public:
   NS_IMETHOD GetNameSpaceManager(nsIScriptNameSpaceManager** aInstancePtr);
   NS_IMETHOD GetSecurityManager(nsIScriptSecurityManager** aInstancePtr);
 
+  NS_IMETHOD ScriptEvaluated(void);
+
   nsresult InitializeExternalClasses();
   nsresult InitializeLiveConnectClasses();
 };
diff --git a/dom/src/events/nsJSEventListener.cpp b/dom/src/events/nsJSEventListener.cpp
index f968ae634579..f6002ab9e7a2 100644
--- a/dom/src/events/nsJSEventListener.cpp
+++ b/dom/src/events/nsJSEventListener.cpp
@@ -95,11 +95,13 @@ nsresult nsJSEventListener::ProcessEvent(nsIDOMEvent* aEvent)
 
   argv[0] = OBJECT_TO_JSVAL(mEventObj);
   if (PR_TRUE == JS_CallFunctionValue(mContext, mJSObj, funval, 1, argv, &result)) {
+    mScriptCX->ScriptEvaluated();
 	  if (JSVAL_IS_BOOLEAN(result) && JSVAL_TO_BOOLEAN(result) == JS_FALSE) {
       return NS_ERROR_FAILURE;
     }
     return NS_OK;
   }
+  mScriptCX->ScriptEvaluated();
 
   return NS_ERROR_FAILURE;
 }