Poker Site 'Lag' with new Dell XPS M1530

Hi,

 I recently purchased a Dell XPS 1530 laptop and so far have been extremely
impressed except for one thing. When I play internet poker on Full Tilt Poker
or PokerStars, I experience a significant amount of 'lag' with the animation and
sound on both sites. The strange thing is though that I do not experience any
problems playing on the iPoker or Microgaming poker networks, and they function
perfectly normal as on my desktop PC and my old medion laptop (both have XP).
Additionally my wireless connection with this laptop appears very stable and fast,
so no problems there.
 So next I tried a 'wired' connection from my laptop to the router and again
experienced the exact same problem, so therefore I believe I have eliminated
the problem being with the wireless network card.
 One of the strangest features of this problem appears when I am playing on
Full Tilt Poker. When the Poker window is active I get very jumpy animation and
delayed sound when either playing or watching a game....however when I move
away from the poker window and activate a non-poker window (say firefox) and then watch
the poker window, the animation appears to return to a more normal smooth
animation without any jumps with missing animation, which to me seems very
very strange. Then when I return to the poker window, it returns to the usual
laggy jumpy animation and sound.
  I have a slightly different problem with Pokerstars being that the animation isn't
jumpy but the sound appears to 'lag' the animation significantly or sometimes disappear
and become silent intermitantly. Another feature is that when I activate the iPoker
software and open a couple of tables, the sound lag on Pokerstars seems to nearly disappear
but not completely, which also is very strange.
 So overall i have no idea what the problem is, but to me I think it may be more related
to the graphics card/drivers or vista operating system than my internet connection,
with some incompatability with the Poker software???
If anyone has experienced similar problems, or could suggest a solution I would be
very interetsed to know as I have bought this laptop to partially play some internet
poker so am not happy with the performance so far.

My Spec is;

Dell XPS 1530,
2048MB 667MHz Dual Channel DDR2 SDRAM [2x1024],
160 gb (7200 rpm) SATA hard disk,
NVIDIA® GeForce™ Go 8400M GS with 128MB dedicated graphic memory,
Intel® Core™ 2 Duo Processor T5450 (1.66 GHz, 667 MHz FSB, 2 MB L2 cache),
Intel® Pro Wireless 3945 802.11a/b/g Mini-Card - Europe - Core 2 Duo Processors,
Vista home Edition,

Also I forgot to mention both these Pokersites work fine with VISTA, as my brother
has a desktop with Vista and plays poker there with no problem.


Thanks.