You if you want to know more on the twin clutch sytem there is an article in F1 Racing Feb '04 on the twin clutch system. There was an analysis on the Maclaren gearbox in the Aug '03 issue.
Here is extract of the article in the Feb '04 issue :
Mclaren's new MP4-19 is almost certain to race with a revolutionary twin clutch gearbox this season, F1 Racing can reveal.
The development of a twin clutch suitable for F1 use has long been a technical holy grail fo F1 engineers, as it enables gear to be changed without the momentary power loss inherent in a single clutch system. The tiny power 'dips' between changes amount to substantial cumulative lost of time over a race ddistance: about 30 seconds from lights to flag, on average.
Despite thte theoretical performance advantages of the system, no team has yet been able to produce one light,robust and small enough for F1 use. Nor has software been sufficiently sophisticated to control the complex process of disengaging one clutch precicly as the other engages.
Maclaren,however, are believed to have advanced to the point where they have sorted out the myraid problems
That was in pitpass section, though it dosen't state the author so I don't know how reliable its, then again it's coming from F1 Racing