tactic trainer buggy ?

Today about 3 times the tactic trainer didnt move on, it kept waiting for my move while i had allready moved. the games seams to hang, when i press F5 to refresh the page i get into another puzzle from which the prvious time has been taken of so i only got a few seconds to solve a 80 sec problem. in effect i loose i think 2 games, and so i dropped 100 points because of some bug.

i'm using the exact same firefox portable version (as i copied it) as i used on windows xp, but only i now was working from a sony vayo netbook with windows 7. but i think this is a server side iseu and not my side.. or .. ?????