Yep,
It's a Motorola-specific problem. The HttpConnection.POST should have been HttpConnection.GET, but then it worked fine with Sun's J2ME Wireless Toolkit. Either Motorola's code is buggy, or the SDK doesn't like being wired into
Java 2 JDK 1.3 (it's meant to use 1.2, I think).
Incidentally, there's a pretty good article on the kind of stuff I was doing at:
http://developer.java.sun.com/developer/technicalArticles/wireless/midpnetwork/ Thanks,
Alex