The following are the main connection related screens from uTorrent on my PC, if you would like to compare. I can confirm that with the settings I'm using, I have no problem with two simultaneous downloads:
My ISP connection is 3072k down / 384k up and 40GB combined up & down monthly transfer allowance, so these settings are tweaked based on this.
If the above settings don't help and you don't mind reconfiguring uTorrent from scratch (as if it was never installed), you can try wiping the complete uTorrent configuration. To do this, go into the "Application Data" folder within your user profile (i.e. click Start -> Run and type in "%userprofile%\Application Data" (including the quotes) and click 'OK'). Then delete (or rename for backup) the uTorrent folder. Note that this does not affect or delete downloads that have already completed.