NEVER EVER use TTimer object for a game! hehe
It's really the most unreliable timer object I know!

GetTickCount is quite accurate, however you can set the accuracy/resolution for this timer, which will also make it run sync on each system...

Code:
// Initialization 
DWORD TickResolution; 
TIMECAPS TimeCaps; 
if (timeGetDevCaps(&TimeCaps, sizeof(TIMECAPS)) == TIMERR_NOERROR) 
{ 
    TickResolution = min(max(TimeCaps.wPeriodMin, 1U), TimeCaps.wPeriodMax); 
    timeBeginPeriod(TickResolution); 
} 

... // All game stuff 

// Cleanup 
timeEndPeriod(TickResolution);
(and yes the code above is C++, taken from here:
http://www.intheoryforum.com/viewtop...asc&highlight=)