I've found that

Subject: I've found that
Name: SickOfItAll
Date: 11/29/2001 11:17:54 AM (GMT-7)
IP Address: 208.1.79.30
In Reply to: That helped a lot! posted by HalOfBorg
Message:

If any other app is using the cam (and this includes an explorer window navigated to the cam, since you can now view your cam through the explorer) it will lock up any other app that tries to access the cam.

The Intel Create & Share software is not XP compatible (they are supposedly working on an update) so don't even try to use it.