N00b question, but I'm having trouble getting a DualShock 3 to link to a PS3. Just upgraded to a slim, and thought while I've got a few controllers I'll try and get the Motorstorm trophy for playing a 4 player split screen race. So the first controller connected ok, the DFGT is seen as no. 3 and an old Sixaxis connected fine as no. 3 - but the DS3 is used on my old phat PS3 just dosn't want to connect. Any suggestions?