Changes to php?

I developed a php-based application with a Flash interface about 1 yr ago. I haven’t used it since then, but have recently revisited it. While it worked perfectly one year ago and I’ve made no changes since then, I can’t get anything to work now.

Can anyone summarize what changes were made to php and/or MySql implementation over the past year? Was anything done that would prevent me from reading from and writing to my mySql databases?

Thanks in advance.