I do not have that problem with log-in every time I change forum topics. Most times I do not log-in unless I reply to a thread which is not often. I do have a problem responding--ex; trying to use quotes in responding to threads.
Wish I could fix the real problem. I don't remember correctly but I think if you use IP config in command mode using local IPS you will find the exact server where you are getting blocked. I cannot find a way to contact this server.
Maybe some tech guru will see this thread and respond. My local IPS was very helpful but only so much they could do.