It's a very common occurrence that's been going on for a while now. Just scrolling down the character list will cause a blue screen. It seems to happen randomly with no rhyme or reason.
It has been happening to me every time I log out of a character and selecting my next character... it seems to happen more if you quickly move the selection up and down from character to character.
I have been a professional programmer since 1997, I believe it is a memory issue, possibly a character(s) index is not maintained correctly and there is an index overflow (basically the characters index goes past its range)