M17X 7970M - Can't enable v-sync in games.

Hi guys. First post here.  I seem to be having a very strange problem with the M17X R4 fitted with a 7970M.

It's a great laptop in every other regard, but I don't seem to be able to enable v-sync in any games.   I've been stress-testing Battlefield 3 and Crysis 2 in particular, with the v-sync option checked and un-checked, running at different resolution/refreshes, and maximising/minimising the window, but the results are always the same.   There's always a constant tearing running down the screen where-ever I turn.

So naturally, the first thing I turned to was the Catalyst Control Panel, where I found the exe's for these games, and forced v-sync for each - but still no luck.

I've also tried reinstalling the AMD drivers (the only ones out right now are rev  8 .938.2 on the Dell website), and uninstalling the Intel HD graphics drivers - which didn't work out.

I'm just wondering if this disabled v-sync is a problem common to the 7970M GPU?  My google powers aren't pulling through right now...has anyone found a solution?

Thanks =)

Cata