This morning I was setting up a scheduled tasks on my Windows 2008 R2 server. I set up the trigger to start at 10 pm on Friday, but when I saved the tasks, the next run time showed something like 4pm on the next Tuesday! Strangely enough, if I query the same task from command line, the next run time is correct.
I found the KB950035 (http://support.microsoft.com/kb/950035) which explains this issue, but when I clicked the link to the hotfix, it only shows Windows Vista for download. Undeterred, I downloaded the hotfix and tried to run on the Windows 2008 server only to be told that the OS is incorrect for the hotfix.
Digging through forums a bit more, I found out that the hotfix is included in the service pack 2 which is recently released. So to fix it, you have to install SP2.