well, I zap once, one goes through as expected, but then a second one gives an error that it goes oer the limit but I didnt zap twice. i wouldnt have caught it if I had zapped ypu 450 and it appears as if you'd have gotten 2 for that amount. could be an issue with the wallet, I don't know, I'd have to really dig in and do a bunch of test zaps from multiple clients to find out.