Issues with crash after changing video card

I was happily running my four eq characters on isboxer for a month or so, but experiencing some lag. Yesterday, I replaced my older (circa 2007) nvidea video card with a saphire AMD HD 6950. I removed the old video drivers and updated the new ones. I found that the first of my eq windows crashes every time now. I uninstalled isboxer and re-downloaded and installed again. Still, the problem continues where the first character crashes either at the character selection screen or shortly after entering the game. Anyone have any suggestions for where the issue/conflict may be?