Performance Issue with Technic

[Sauropod]

I have an interesting performance issue with, I believe Technic itself - I say that because when I play Minecraft in native mode I experience no problem whatsoever, when I choose Vanilla on the Technic Launcher I experience what can best be described as a 'lag' effect.

I have allocated 2GB Memory and have the option "Increase PermGen Size" selected.

Machine is a 2.8 GHz Core i7 running OS X 10.8.3. with 16GB Memory.

I suspect something to do with the latest build of the Technic Launcher because I last played (without problems) 6 weeks ago, but took the latest build yesterday evening before trying to play.

Thanks in advance.

[Sauropod]

Further to my post above - I have used TimeMachine to revert to Technic Launcher 1.0.2.0 - no performance issue any more!