Error Uploading Through Proxy Server

The error message below probably indicates a bug in the proxy server. On the other hand, we probably don't want to argue with the administrators about this but to find a work-around.

Any suggestions?

Server: squid/2.6.STABLE14
Date: Mon, 05 Jan 2009 17:41:17 GMT
Content-Type: text/html
Content-Length: 1056
Expires: Mon, 05 Jan 2009 17:41:17 GMT
X-Squid-Error: ERR_ZERO_SIZE_OBJECT 0
. . .
Via: 1.0 *.*.*.*:* (squid/2.6.STABLE14)