complete computer lockup when uploading sketches

Hi,

Im having a weird problem. occationaly (~1 in 15) uploads to the arduino will result in my computer completely locking up (ie screen freezes completely, mouse doesnt move etc). this seems to be happening at different stages of the upload process, as sometimes the sketch will run, othertime the arduino will hang as well. my specs are listed below

Thanks

Spec: Sony Vaio VGN-NS15GS Laptop Windows 7 x64 (driver via windows update)

I've seen this a few times, same OS and specs.

I just tried installing the newest JRE on the machine, and deleting the java folder in the arduino-0017 folder. Uploaded a few dozen times and haven't seen a lockup yet, but time will tell.

im guessing its a driver issue (if it was java you'd just see the IDE lockup, mouse/keyboard etc would still be responsive). ive tried putting a usb hub between the arduino and the laptop, will update in a couple of days with results