Community of Sexsoundlovers

When I use the login link from the start page at the upper right corner and I enter my username and password to the login form I get the following error message:
"The submitted form was invalid. Try submitting again."

I then use the login form from the bottom and I can login. Since a few month ago I always used the login form from the top right link without problems. Any ideas?

That is a problem I haven´t heard of before and so I have no idea yet. Does anybody experience the same?