W3WP recycle return codes

I have an IIS6 machine, running multiple web applications. Once in a while, IIS recycles W3WP. When i look at the error codes, W3WP.exe usually exits with return code -2 (0xfffffffe) but one in a while it exits with -3 (0xfffffffd). While the end result is the same, i was wondering if there's any difference/reason to these particular return codes?

According to this post, -3 indicates that WAS (Windows Process Activation Service) had to kill a worker process, whereas -2 means that the process closed OK.

So I suspect that when you see -3, it means that the worker process was doing something at the time it was recycled, but -2 means the worker process wasn't busy and was OK with just quitting when asked.