I'd been using a Motorola H350 since release, with *very* limited success. Basically, it would occasionally turn off my controllers!
I've since bought some Sony-Ericsson thing, which is *vastly* superior. It was about £30 for a supermarket. I can't fault it to be honest.
Having done a bit of research ALL motorola headsets have connectivity problems with the PS3, so steer clear!
I had a motorola, the same model as you and it was rubbish.
USB headset for the win, always works and its more comfortable / better sound quality.

but this is the one Samsung WEP170 Bluetooth headset and the place i bought it from has put the price up so it's £19 now but they are now doing a Sony Ericsson HBH PV702 Bluetooth Headset for £13.49 with good user feedback .
If we pick a decent headset and all use the same one then we should have no problems talking to each other. Bluetooth headsets are quite iffy, so maybe we should go for that Logitech USB one on the Australian river.