Bug Report: Java Web Start download uses illegal If-Modified-Since header
I just created a bug report (internal review ID of 1460085) that includes a proposed fix based on JDK6u12 source. I have already EMailed a PDF of a signed Sun Contributor Agreement just in case this is needed or will expedite things. This bug also exists in the latest openjdk7 source drop and does not exist in JDK5.
3-1/2 months ago I created a less specific bug report (internal review ID of 1380005) that so far is unreviewed. This older bug can now be closed. The newer report is much more specific and includes a proposed (and trivial) fix.
For anyone deploying Java Web Start across a WAN, this fix will make a big difference. I hope this fix can be included in 6u13 or 6u14 (which is why I am posting here).