Okay, so I just did a complete re-install, but I'm still having the same problem. I even installed the sample data and list, but the error is still there.
Here's an interesting thing I noticed, however: Whoever is at the top of the full user list does not cause an error. The screen momentarily refreshes when I click on the row, but there is no error. If I change their name so they move elsewhere in the list, then clicking them will cause the error. At which point, whoever is in the new top position no longer causes an error.
When I run a search to narrow down the results, I don't get an error, but I don't get the refresh either, instead I get redirected to index.php.
So I'm getting 3 different results here: error, refresh, and redirect based on slightly different circumstances. The thing is I don't even know what the correct results I'm looking for happens to be... What is SUPPOSED to happen when I click on a user's row? (Not on the hyperlink or the image, but anywhere else on the row?)
-Matt