I have been having printer proxy hang issues. Apple Tech Support has bounced me all the way to the top -- to the software engineers. After they received a Capture Data File from me, here is part of the e-mail they sent me:
The log files from this customer's system are somewhat difficult to read because a set of messages keeps being written to the log every 10 seconds:
com.apple.launchd[99] (com.avast.MacAvast[6114]): posix_spawnp("/Applications/avast!.app/Contents/MacOS/avast!", ...): No such file or directory
com.apple.launchd[99] (com.avast.MacAvast[6114]): Exited with exit code: 1
com.apple.launchd[99] (com.avast.MacAvast): Throttling respawn: Will start in 10 seconds
If the customer has deleted the avast! antivirus software from their /Applications folder, they also need to remove the launch daemon that is causing launchd to try launching it every 10 seconds. They should remove items related to avast! in /Library/LaunchDaemons, /Library/LaunchAgents, /System/Library/LaunchDaemons, and /System/Library/LaunchAgents (the last two locations normally only include software that is part of Mac OS X). Refer the customer to avast! support if they need more information on completely removing this software from their computer.
Okay! I officially admit complete confusion -- because I cannot find any of the LaunchDaemon/LaunchAgent entries, yet Apple Tech Support tells me that the log entries still record that the Avast! launch daemon is still trying to launch it every 10 seconds. 
H E L P !!
Yes, that's the damn launchd - daemon, responsible for running tasks or keeping them in running state. It's controlled by plist, and user can add/remove items there using the launchctl utility.
Just delete the avast's record there - btw. launchd is stupid enough to start aps outside their context (common flaw on 10.4.x), in 10.5, it's "fixed"
man launchctl
man launchd
man launchd.plist
nice, huh>?
pc
