weird errors when user can't login

When a user incorrectly enters their name or password, I get these errors in my error log:

Type: error
Date: Sunday, 07 November 2004 - 17:06
User: Anonymous
Location: /user/login
Message: warning: implode(): Bad arguments. in /path/to/modules/taxonomy_access/taxonomy_access.module on line 125.

Type: error
Date: Sunday, 07 November 2004 - 17:06
User: Anonymous
Location: /user/login
Message: warning: array_keys(): The first argument should be an array in /path/to/modules/taxonomy_access/taxonomy_access.module on line 125.

I get each of these listed twice for every failed login. Don't know why. Doesn't seem to be a huge deal, but who knows.