The game image can 'simply be' a iso, bin/cue and some other common filetypes.Ideas that come to mind;
 Just extravagating on earlyer comments; it cannot be stressed enough that the free version and payed version no longer work together (at this point anyway, im very sure they will again in the future) so make sure you remove everything FPSECE related before installing the supporter version.
 Also, the order in which the install packages are mentioned in the email u got, you should always install in the same order.
 A last thing i could think of, when u reinstalled all again, and it still wont work, you might want to have a look at gameslist.ini in the fpsece directory, theres a slight chance that your rip of your original disc actually works different then say a us/eu/jap version already listed in gameslist.ini, look trough it and remove any grand tourismo related lines.
 Still not working?? time to look for a grand turismo thread in this part of the forum: http://www.fpsece.net/forum2/viewforum.php?f=35
(or make one when it doesnt exists)