I've got the same problem with my computer(s) at work. Both computers are HP xw6400 Workstations running Windows XP Pro.
It started a while ago (I think it was around the 7.4 update). When the Quicktime file is stored on a network drive, I'm not even able to delete it with another computer, untill I log my other computer off or shut it down.
Can it be caused by other programs?
I have Adobe After Effects 6.5, Photoshop CS, Illustrator CS, Encore 2.0 and Autodesk 3d Studio Max 2009 installed on my machine. The other one has Adobe CS3 Production Premium and Autodesk 3d Studio Max 2009 installed.
I hope they are coming with a solution for this very soon!
p.s. Lawyerjim, I don't get the message "com surrogate has stopped working", so I think thats not the problem.