Dippsy – Paypal – 500 Error appeared?

I set up an online downloads store using the Dippsy plugin up to last night I had no issues.

Originally the shop was set up with the artists mp3’s, I tested the downloads which go via paypal and everything ran smoothly. Payment – confirmation – download link email.

I was asked to put up a .zip file of all the tracks as a full album download, it took some tweaking as the file was bigger than the uploads would allow but I uploaded a php.ini file I found from a solution online and was able to upload the .zip file and add it to the store.
this is the php.ini file used

After this I tested the store, payment was made but no return download link.
The IPN history keeps saying Retrying in the paypal account.

I’ve spoken to paypal who tell me it’s a problem with the script, but I haven’t changed the script? Only added a php.ini file ?

I’ve downloaded the log file from dippsy folder where the mp3 and zip files are held and the logs say invalid email and invalid price.

Again the email address hasn’t changed and the price is 0.03 for testing purposes.

Has anyone else encountered this problem ? Any ideas why this would happen ?