attachment upload prob. on production server

Hi all,

I am having prob uploading an image. Using acts_as_attachment plugin with rails 1.1.6 and as far as I know there is lighttpd and fastCGI servers. Here is what we've got from there:

Proxy Error The proxy server received an invalid response from an upstream server.

The proxy server could not handle the request POST /meetmarket_submission/thumb.

Reason: Unsupported Transfer-Encoding chunked "image"=>{"attachment"=>#<File: /tmp/CGI.12987.0>}} from remote server

Apache/1.3.37 Server at <...> Port 443

Locally everything is working fine, this raises on production only. Any clues how can I fix it?

Thank you a lot! Pavlo