restarting Inetinfo

Once in a while I get the error:

Inetinfo terminated unexpectedly and the system was not configured to
restart IIS Admin. The World Wide Web Publishing Service has shut
down.

If I look at the IIS Admin service its "Recovery" option is to "run a
program" (on first, second, subsequent failures) and that program is:


C:\WINDOWS\system32\iisreset.exe
with command line parameters
/start


so why isn't IIS restarting on my box?

this is IIS 6 on Windows Server 2003.