It's been a while since the U.S. invaded Afghanistan. Looks like they are concerned about fundamentalists reactions to a continuing U.S. presence. http://www.cnn.com/2005/WORLD/asiapcf/08/26/uzbek.us.ap/index.html .
Fuck Uzbekistan, their record on human rights is pretty shitty (I know the U.S. ain't exactly sterling in this aspect, but still it ain't as bad) from human rights watch (not to be confused with the gay advocacy group The Human Rights Campaign) http://www.hrw.org/wr2k1/europe/uzbekistan.html
The U.S. was supporting an investigation of the recent crackdowns over there. That may be a reason the Uzbek govt wasn't favorable to the U.S. this time around. .