I saved a puzzle at about 2am GMT and it took between 1 and 3 minutes before it was actually saved. Sorry I can't be more precise, I wasn't actually paying attention to the hour. Two subsequent saves were immediate. But now (2:43am GMT) when I finished the puzzle it is still trying to register so since about four minutes.
I got the score failed dialog box at 2:46am, hit the retry and am waiting again....(while waiting I discovered that one can make funny drawings on the screen with the frozen applet

) Got an,other score failed dialog at 2:49; retry; wait;...
Got another Send score failed dialog box at 2:54am GMT BUT the puzzle shows as registered on the Details Tab in iGridd. I'm going to risk it and click 'No'. Hmmm, more waiting....
Unfrozen at 3:09am and luckily the puzzle is indeed registered. Phew.