(Members) Cannot login to site

For some reason, members cannot login to the site.  I reset their passwords, created new accounts, etc.  Nothing works.  I keeps on saying incorrect username or password.  

Anyone experience this before?  Anyone know how to fix this? 

Can i have your site admin pm me..Ill check it for you.

Good question because I have one member that routinely is locked out of our site for entering wrong credentials.  What I think is happening with her is that her keyboard is repeating when she hits submits and she submits the wrong credentials several times.  I am using AMS 2.0 and it has a lockout if someone attempts to hack into an account; she claims she only tried once or twice before getting locked out when I have it set on seven attempts before any lockout.

It seems to happen when you (I) enable the spam IP filters.  All members, including myself were locked out.  However, when I logged in via admin, not a problem.  

 There is a spam list in Dolphin 7.0 called "zomgbl.spameatingmonkey.net." If you enable it every IP will be blocked including yours. It doesn't block admin in order to prevent you from being locked out completely.