I've seen oddball behavior with POST once before: a client, who I won't mention, had a not-so-great firewall configured and managed by another vendor. The client was trying to post replies to questions on a message board on their website (which was hosted by the company I was working for at the time), but the replies kept getting cut off at 5K. It turns out the firewall itself was truncating the POST requests.... So it wouldn't surprise me one bit if a badly behaving proxy server were converting POSTs to GETs -- especially if it were a proxy designed to cache requests (since you can more readily cache the response to a GET than the response to a POST).

Spud Zeppelin * spud@spudzeppelin.com