Considering that FlashFXP is a user-land application, it is almost impossible for it cause Windows to bugcheck (aka bluescreen). Are you using Windows XP x86 edition or x64 edition?
Could you provide more information about the bugcheck, such as the stop address and module name? This problem is more than likely caused by a buggy driver installed on your system. If you are running Windows XP SP2 x64, this wouldn't surprise me since some vendors are pushing x64 drivers out the door too quickly.
