Running Vista SP2. If User Account Contorl (UAC) is on, Reader 9.1 will open and disply the first page of ducument, then freezes and can only be closed via the task manager. This happens both when running Reader as a stand-alone, or through Firefox or IE. If I open Reader directly rather than by clickiing a file, it locks up right away.
The usual UAC warning does *not* appear. The reader opens fine and then locks up.
This also prevents 9.1 from being removed or updated while UAC is on. It gets almost thru the process, then throws an error message (something about being unable to get something from V8) then stops.
This does not affect Reader v 8. All works OK if UAC is turned off (but then I get that annoying reminder to check my security settings.)
Turn UAC off and pray that Windows 7 fixes the problem.