As of about 2 days ago I keep getting a "you need to be logged in to do that" type of message when I reply to topics or PMs, but it's COMPLETELY random. I think clearing my cache, and such helps but no idea if it fixes it. The problem with this is how random it is. I'll be fine all day, and then I have a large reply, or PM and bam... weird error(also seems to eat my message.)
Any idea what might be causing this. I've had it happen with Firefox, Avant Browser, and on Opera so far. Only just started 2 days ago too.