Paypal IPN fails possibly due to fraud?

[FONT=Times]Payments from my website continue to be logged on paypal.com, but the IPN script is not processing those transactions in my database. Members who have upgraded are complaining that they are not getting access to the paid features. The odd thing is, I have not touched the IPN script, written in PHP, for months! I’m baffled as to why it suddenly stopped working, so are the tech support boys at Paypal. I’m convinced it has something to do with the fraud that took place on my merchant account this past weekend, but Paypal denies it.

Any ideas on what could be causing this considering the script has worked great for two years and has not been tweaked for months?

Thanks![/FONT]

Earlier this year (or perhaps late last year), PayPal changed things significantly in this regard—updated its API or something. Did you upgrade back then? The PayPal cart I was using became outdated at that time, and whole new script needed to be installed for it to run again, although I didn’t bother and just dumped PP altogether. Are you sure when things stopped working?