I believe we tracked it down to the sending machine (an IBM mainframe) writing the encrypted
bytestream out to a FB (Fixed Blocked) dataset. This results in the PGP datastream being padded
out to a specific width as defined in the DCB. When gpg tries to decrypt this, it finds these
padding bytes and all hell breaks loose with a variety of different errors.

Can someone tell me how I can get "invalid packet messages", followed by "decryption ok", ending in a
return code 2 and still produce a file I can find no issues with?

I've just noticed that I'm even getting some warnings about invalid packets on a SHA1 digest file - a 660
byte PGP file, which produces an EBCDIC 40 byte SHA1 digest file.

Hi Werner,