I think your original problem might be related to http://www.compiz.org/Workspace_Switcher_Fix as I was experiencing similar problems.
It is not a particularly elegant fix, but the second part did the trick for me: I set /apps/metacity/general/num_workspaces to "1" and left my settings in /apps/compiz/general/screen0/options/ at their defaults. This means that I have set number_of_desktops in /apps/compiz/general/screen0/options/ to "1" (looks like this should always be the same as /apps/metacity/general/num_workspaces) and hsize to "4", which gives me 4 virtual desktops (that all stay on the same cube). Hope this helps and that this gets fixed in future versions, because it is strange that it is necessary to change metacity's settings to fix compiz. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]