About two months ago, I posted this same problem and then by using a proxy, I was able to browse. A few days after that, the use of proxy wasn't needed and the problem mysteriouly disappeared, anyway;
When I get to the log on page, I enter my username and password. About half the time, it accepts and I can see my stats at the top; upload/download, etc. I can even access my userpanel. However, upon hitting browse, it logs me out and then when I enter my password etc to get back in, it doesn't accept it, but also doesn't take the number of incorrect guesses down either. If I go to another site, and come back, this whole process starts all over whereby I enter my username and password and it accepts and I can see my stats at the top. Grrrrrrr.