I have 2 Users that can't login because..
 

They get to the login screen, enter their credentials, then it bounces them back to the login screen again? Anyone have this happen? :confused:

Yes, I have this same error on my forums as well....The temp solution is not to use the login script that appears in the middle of the page, but instead use the smaller login script that is in the top right hand corner of the page. For some reason that script works and the other doesn't. I haven't figured out the reason it works like that nor have I figured out the cause.

tell them to clear their cookies and cache and try agian

I've done that! No work.

--------------- Added [DATE]1204842692[/DATE] at [TIME]1204842692[/TIME] ---------------

I will give them that option as a way around it. Thank you.

Please create a new Style with no Parent set. Now browse the forum using this new style, do you still have the same problems? If you are troubleshooting login or guest issues, you will need to set this style as board default in the vBulletin Options.

Ok, that worked nicely. So it is a style that causing the error? What would I need to do to fix it?

I'm not familiar with doing that, are you saying revert back to default (by creating a new style) with no hacks on it, etc? I would rather not take my forum back to it's original setup just to check login issues :(

Create a new style, with no parent set. The link is found at the bottom of the Style Manager page.