I know this is an old thread, but I found a solution and thought I share it with everyone.
Microsoft article 833007 (site does not let me paste link, go to "support dot microsoft dot com forward-slash kb forward-slash 833007") provides solution for controlling these through Registry.
It outlines instructions for Office 2003 (i.e. Office 11) but same technique works for Office 2007 (i.e. Office 12). The only difference is you must change all instances of "\11.0\" in the registry paths to "\12.0\"