Quote Originally Posted by katank
Franconicus is right about the unlocking faction part. I recommend against hitting the Senate tab while playing Senate as it crashes the game. Also, playing rebels is occasionally glitchy.

Another friendly piece of advice is please do not post your email for spambots to crawl. It will lead to abundant spam. At least do something like htg04[at]yahoo.com which is very readable by humans but not by crawlers.
The reason the Senate Tab crashes the game is your graphics card... It is probably only 32 Mb of memory. I too, had this problem until I updated to a 64 Mb graphics card...