Boxing Issues.

I've been having an issue where one or both of my accounts will crash for no apparent reason. I.E. was PLing my second account's low level jobs by doing books in Zeruhn Mines for it with my Main and both windows randomly crashed after a fight while standing there.

I use Vista 64-bit and have no issues if I run only 1 account, it seems to only happen when I try to box 2.

Get a crash dump. You can find everything you need here:

http://wiki.windower.net/display/Windower/Crashdump

Thanks a lot ^_^ I'll make sure to do that next time it happens!

Well, you have to have it running before it happens. So run one on both instances of your games and then do whatever causes you to crash most often, if you are even aware of anything. It can be kinda quirky to run for long periods of time so I wouldn't do it while you're doing anything important.