>In Device Manager, how does that monitor appear? If it's "Generic PnP Monitor" you could try downloading the exact .INF file for your monitor and installing that - additional refresh rates may appear. My monitor shows 59Hz and 60Hz as available options; I'm using the former.

It is Generic PnP Monitor. I do not know if they released one specific file for that one. The last time I checked there wasn't any. But, my guess is that something new in SP1 triggers that reaction and maybe an updated file from Acer might do it.