Can't reply

Not sure if this happens to anyone else or if this problem has already been posted-- but if i go to reply to a thread, the normal reply screen comes up, but i cant click on anything.  Like all of the buttons above the box (bold, italic, underline, add picture, hyperlink, etc..) are all un-clickable, and the box in which you type wont have a cursor, and I'll try and click in the box a million times to produce a cursor, I'll right click, left click, refresh the screen-- nothing helps it. The only way I can get out of it, is going back to the thread and trying to reply again, sometimes, I'll have to do this 4-5 times before I'm able to get a cursor in the reply box.