I'm posting this so 1 I won't forget and also maybe someone else may know of a possible problem.
I use Theme My login plugin to let my users login and register with customized emails etc etc. All was working fine with the previous version. I used the automatic update in the dashboard section.
Then I started getting reports of not being able to register to my site.
When I tried to click on register it does nothing but refresh the page.
I had to get the problem fixed quick so I narrowed it down to the W3 total cache upgrade I did today. Now with w3 disabled it is working ok.
I'm short on time at the moment but just wondering what may have changed?
I did clear all caches etc but it did not make any difference.