Paypal Payment Goes Through but Pro Status Not Renewed?

We've been encountering a troubling bug on our Pro Sites installation.

We currently have over 30 active Pro Site installations on our WP/BP site.
Quite a few of those are "manually" created, but several are also paying users.

Our site has been up for a relatively short time, and we recently passed the "one month" point of when we unveiled our Pro Sites package. We didn't have any problems with folks paying the initial months payment and getting Pro status, but NOW a month later we have had 2 different users have their Pro status revoked AFTER successfully making an automated Paypal subscription payment.

We have transaction IDs from our customers verifying that they paid, and indeed our paypal account is showing that the money WAS received. But the 2 users in this situation did not get another month of Pro status added to their site as we would expect would happen. Instead they were downgraded to Free and I had to manually add a month to their account.

Obviously moving forward this is a VERY bad thing and we would greatly appreciate any help in troubleshooting this issue as soon as possible.

Thanks!

Tyler
Middle-earth Network