I don't have a fix, but my tests produced the same results.
I disabled RAV and allowed the message through, then reenabled it.
I believe that there is a circular problem somewhere in the code, but I haven't taken a closer look yet. To me it appears to bounce the message, then scan the bounced message, then bounce that message, etc, etc.
Darrell released a patch recently. I haven't tested it to see if it fixes this problem though.