Profiling vim

Hi,

since recently vim is maxing out my CPU a while after a file is
loaded. It's definitely caused by my .vimrc (maybe a plugin?) Plain
vim doesn't exhibit the behaviour. Is there a simple method to tell
what it's doing while hitting the CPU? I tried using the build-in
profiling commands, but it doesn't seem to work. What I did:

vim -c 'profile start log' somefile
# wait some time
:q

But the log file is empty.

Otherwise I have to bisect my .vimrc, which I want to prevent, since
it will be tedious as there's a time delay between loading the file
and vim hitting my CPU. (Gosh, I'm happy vim is single-threaded :)


Marco