Is it safe to assume that if a school has cashed your check, they have received your supp. application? Or, have you all been calling the schools to check if they have been received?
I am lucky in that I can check my bank activity in the evenings over the internet. I just gave reasonable time for the schools to send the checks through, and checked with my bank.
Luckily, most of them contacted me before the check went through.
If you can't check your account activity online, just call the bank and ask if that check number has cleared. If not, you could call the school itself, but I wouldn't want to bug them any more than necessary. 🙂