Please read Announcement at top of this forum which deals with this 1/2 wmv display problem which was caused by a recent Windows Updates.
There are several threads in Discussion already.
If you have any problems finding the Announcement and finding the current threads here on the problem, please post back.
It appears this is the answer, unfortunately. Confirmed it today while working within Premiere Pro.
The workaround my colleague used was to convert them to another format first, and then she imported them into her project. It seems that has bypassed the issue for now without having to do any major lifting.
I had read that message before I posted, but didn't think it applied at first.
Thanks for the follow up which is important to all.
Glad all worked out well for you.
Any further flare ups on this issue, please let us know. Some have had to resort to the following to make sure the offending kb was really gone
a. For now, set Windows Updates so that notification is required for any downloading plus installing (oldevhs suggestion)
b. If you catch the offending kb beforehand in Windows Update Important Updates, just right click it and select Hide (nealeh suggestion).