Hi -Natas-
Correct me if I'm wrong but the ? symbol that you see is actually the TM symbol. If you want to change the name you are going to have to rename the game name in the default.xbe either using Avalaunch or other progrmas out there.
Just make sure you make a backup copy of your games defalut.xbe in case something goes wrong.
If you still have your original Xbox dash and you go to the memory manager you can see the TM symbol after the name.
Hope this helped but I might be wrong on this one, wait a liitle longer for either UnleashX or someone else confirm this.
GreetZ
<Edit> To change the games default name with Avalaunch go to File Manager and highlight the default.xbe you want to change and press Start a little window will pop up and choose Edit XBE Title and a virtual keyboard will pop up and press Y to save changes and exit and ReBoot that should do the trick. Maybe UnleashX can add this little fitchure as I do not see it there, if it's there than my appologies to UnleashX<Edit>