BB playbook won't always let me type a reply

Hi, sometimes (like 10 mins ago), I can't type on the forum without the text getting messed up. Every word takes an age to type and messes up. Missed letters, capital letters mid sentence etc. The text takes ages to appear after typing. Then, like now, it is suddenly ok. Any ideas?
I can add a new tab, like Google, and it's fine. I switch back to here though, and it won't type.
For an example.......see the photos from the past Page. It's doing my nut in.