Crash short after quest item drops

The game crashes almost every time short after a quest item drops from a boss. I've had it with the spear and now with the medicine chest. It has crashed a few times before I was able to pick it up (suppose I don't need to mention that's quite annoying ;) ) but also right after I picked it up. If I had to guess, I'd say it's about 2-3 seconds after the item dropped, and I think it has only crashed while I'm moving, don't know if that's got anything to do with it.

My system:

OS: Windows Vista Home Premium 64bit, SP 2
CPU: Intel Core i7 2.67 GHz
Gfx: AMD Radeon HD 6900 Series
Driver: v8.95 - Catalyst: v12.3

If you need more info, I could try out some things (eg, try to time the seconds between drop & crash, try not moving, try picking it up asap,...)

Oops, duplicate of http://www.pathofexile.com/forum/view-thread/25639
Nothing came out of the PackCheck.

Haven't had it for a long time - must have been about 5 spears and medicine chests that went well - but now it crashed again. Only about half a second after the drop. Might be related to the witch ? Didn't have it with my other characters. Must say that I did always try to pick up the quest item as soon as it dropped though.