uTorrent keeps crashing (after upgrade to Mavericks)
The 1.8 version of uTorrent isn't updated for Mountain Lion notifications and the malloc errors you posted indicate a fairly severe memory management problem. Unless an update past 1.8.4 gets released, you might try running the 1.9 beta version as it has memory leak corrections listed in the release notes. 

It contemplates newer OS explicitly and the fix for this error might arrive there first or exclusively. 

http://www.utorrent.com/downloads/mac