can't login to profile on my site

Can anybody figure out why this would happen? Nobody seems to be able to figure it out. Admin login works but members can't login. Dolphin has been a nightmare!

I am not sure what version of dolphin your running.

Check admin->tools-Anti Spam Tools. Are any of them enabled?

Try settings->advanced settings->Security

Uncheck these 3 settings.

Enable DNS Block Lists:    
Enable URI DNS Block Lists:    
Enable Akismet:

Also look in tools->ip blacklists. Remove any blocked ip's

Depending on the version of dolphin your running, some of these might not be available.