I was able to get an absurdly high number like that on a friend's computer that ran the game slightly slower for some reason or other.
I'd like to note that the computer there does not lag on flash (unless it's really heavily coded). It's just the screen that was really old at the time (17" CRT). The trick is to not bother with all bells. Often skip every other bell, but always aim for the bonus bird to double your current score. If you keep aiming for all the bells, you'll get tired/bored sooner and get less birds. Imagine if I had taken 6 more birds - I'd have two more digits for just 30(?) seconds.
As for your reason to not play it again, I completely agree. Too addictive. ;p
