invalid argument in user profile - related to flag content

Issue Summary

Hi -

I was having an "invalid argument" pop up on user pages and a drupal search led me to another a conversation - http://drupal.org/node/166637 - that tipped me off it was related to "flag content."

Looks like if I don't enable "flag user" I get an "invalid argument" message on user profile pages. Any idea how this glitch can be corrected - either by setting things differently on my end - or some patch I can put in? I actually don't know the first thing about php, but I can access module files and edit them - if i'm given careful instructions.

Thanks!