This may also happen in earlier versions but the bug only manifest itself now,
because of timing conditions in a multi-threaded environment. 

To reproduce install a couple of extension, for example
desktop/test/deployment/update/publisher. Then press the Updates button and
click install. When downloading is finished and installation begins then press
Abort. Restart the office. Open the Extension Manager and try to expand the My
Extensions, or StarOffice Extensions node (wherever the extensions were
installed). A message box will appear complaining that a particular extension
does not exist. Even worse, all other extensions are not displayed anymore. 

When clicking again the Updates button then no updates are found anymore. One
can mark the "Show all" checkbox but the list contains only an error and no
text. At this time the Office crashes. This however, may be a side-effect of the
corrup Extension Manager data base.