Multi-tasking and multi-tabling

I'm not sure why, but I just can't play the same game while I'm multi-tabling. Part of obstacle is a very small monitor on my mac powerbook. For the first time, I've bought myself a decent sized monitor (19", which is actually small these days with 22" widescreens emerging as the norm). But it's still not big enough for serious multi-tabling.

Even playing a freeroll, a minimally mind-intensive sort of poker, I lose my edge in the cash game. Have to concentrate on one with so many players coming and going.