I am using the latest version of the Force.com IDE 64-bit for Windows.  Every time I attempt to edit a page the application locks and will not respond.  Here is a dump of the log file.  This is a vanilla install straight from Force.com.

!ENTRY com.salesforce.ide.core 0 0 2010-06-16 08:00:39.807!MESSAGE DEBUG [2010-06-16 08:00:39,807] (ComponentFactory.java:getCompositeComponentFromFile:1037) - Loaded ApexPage 'pages/StoreFront.page' [unpackaged] from file 'StoreFront.page'

!ENTRY com.salesforce.ide.core 0 0 2010-06-16 08:00:39.808!MESSAGE DEBUG [2010-06-16 08:00:39,808] (BaseComponentMultiPageEditorPart.java:setInput:118) - Set metadata editor input from source file 'StoreFront.page-meta.xml'

!ENTRY com.salesforce.ide.core 0 0 2010-06-16 08:00:39.809!MESSAGE DEBUG [2010-06-16 08:00:39,808] (BaseComponentMultiPageEditorPart.java:setInput:139) - Opening ApexPage 'pages/StoreFront.page' [unpackaged] from file 'StoreFront.page'

!ENTRY org.eclipse.wst.validation 4 0 2010-06-16 08:00:47.603!MESSAGE IWAE0017E Cannot create validator org.eclipse.wst.common.componentcore.internal.ModuleCoreValidator because a Throwable was caught.
!ENTRY org.eclipse.wst.validation 4 0 2010-06-16 08:00:47.603!MESSAGE Plug-in org.eclipse.wst.common.modulecore was unable to load class org.eclipse.wst.common.componentcore.internal.ModuleCoreValidator.
!ENTRY org.eclipse.ui 4 0 2010-06-16 08:00:48.308!MESSAGE Unhandled event loop exception
!ENTRY org.eclipse.core.jobs 4 2 2010-06-16 08:00:49.371!MESSAGE An internal error occurred during: "Processing Dirty Regions".