I remember reading several fixes for various issues, one was fixing the games resolution and the other was lowering the video settings prior to log in.
www.aiononline.com they had a few links that may help
I would suspect lowering the video settings may stop you from crashing before you have a chance to log in.
But who knows...they still havnt admitted they have a sever memory link in highly populated areas.
Ive found 99% of the time my client crashes Aion is sucking up over 2GB of memory, I believe once an application hits over 2GB it crashes in windows.
Only becomes an issue in town...and I here will be an issue during sieges.