In fact, this happens all the time if you use the Selenium proxy; since we now alwaysProxy by default, this happens quite frequently.

The problem is that ProxyHandler.java assumes that if the browser's HTTP request includes a Content-Type header, then the browser's request must therefore contain content. In that case, ProxyHandler forcibly changes the method to POST.

(For some unknowable reason, the browser JRE plugin passes a Content-Type on its jar GET requests; this is semantically incorrect, unless the browser is trying to send a JAR to the server in the body of a GET request!)

Anyway, I've checked in a fix in RC revision 1939 to address this case. Now we assume that a GET request has no body, even if the GET request includes a Content-Type header.

In investigating this problem I found and fixed SRC-326, which is a much more serious problem that would totally break applets. I suspect that SRC-132 may have been misdiagnosed as the cause of more general problems with applets, since doing an empty POST seemed not to harm anything; anyway, applets seem to work better now in PI mode. My test case was
http://java.sun.com/docs/books/tutorial/uiswing/components/applet.html. (Don't forget to clear your Java cache using the Java Control Panel before attempting to test this fix.)

Oops, forgot to mark this closed. This was fixed for 0.9.2 in rc revision 1939.