What firmware you on ?
I hate 20 chars

for which console, my fat (jailbroken) is on 3.55 and my regular ofw ps3 slim is on 4.46.

3.55 cfw is crap and a updated mw2 aint gonna work unless you resign the Eboot to work on 3.55 as it reqs 3.60 +
You won't even be able to data transfer
Update to a decent new cfw.

what firmware do you suggest I use

sn))((
Rogero 4.46 its ready for online,any game,data transferring,no spoofers its noob proof.
Thats why I said install it from the off.
Have faith

ok so I install rogero 4.46 on my fat console, then if I want to host an online mod menu(like in private match) I would select patch on file manager, once im done on file manager I would data transfer and it would work correct.

I'm not sure what you mean.
But you can on your Cfw change your patch and host it quickly.
If you wish you can data transfer to your Ofw and host on your Ofw.
You really dont need to transfer its your choice.

kk what im saying is in comgenies awesome file manager you have to go through the things and select your patch and copy it over, correct. after its copied over I quit game and then data transfer and I will be all good right.

oh and what do I do for my game data utlity, do I install any special mw2 package or

Turn your Xbox on, get ear buds and stick them into your fans and leave them there for around twenty minutes. Then turn your Xbox off, all pug it and plug it back in. It worked for me