Not sure how to describe this latest oddity, but here goes...

Starting about a week ago on my work PC, it seems that some videos (e.g., clips on YouTube.com, flash video, etc) - even though they appear to load all the way (progress bar fills up completely) - decide to randomly stop playing after a certain point (different in each video), while other videos play right through to the end. Once they're stunted, you can't get them to play past that particular point without rebooting.

For example, there's an interview video on YouTube that I tried playing after letting it load completely in the browser window. It played til around 1 min & 35 seconds, then abruptly stopped. I couldn't force it past it, refreshing the page didn't help (still stopped at the same point afterward), but after rebooting, it stopped at a different point (around :51). I then loaded up some flash video (Strong Bad email @ homestarrunner.com), which played about half of the way through, then stopped.

What could cause this to occur? My hard drive has 19 gigs of space left, and my IE settings are set to store only 1 MB of temp files. As always, any help would be greatly appreciated.

Does your work PC have any kind of restrictions to on-line use? Time outs? etc.

Look in your Event viewer: rt. click My Computer then click Manage then Event Viewer.
Or: Administrative Tools/Event Viewer or Start/Run/ eventvwr
Open the system as well as the application tabs & look for red X errors. Click error line for details.
Post back the source & event id & Description especially of errors that seem to coincide with this issue.
Also check the Information lines that might coincide with this issue.

How to view and manage event logs in Event Viewer in Windows XP