Not sure if this is operator error or a bug, but it appears to be a bug. Under 1.3, using ProxyPass and ProxyReverse within an SSL VirtualHost, one could add an SSL front-end to a second server that may not support SSL. This configuration doesn't seem to work under 2.0.35. On my configuration, SSL virtual hosts work fine, and both forward and reverse proxy virtual hosts work fine when they are not SSL. An SSL virtual host with a reverse proxy, however, connects (verified using openssl's s_client command), but never responds. Commenting out the reverse proxy lines on that exact virtual host causes the default apache HTML pages to come up, so the SSL isn't the problem. Also, the remote server does see the socket opened by the proxy, but does not receive any data. (Verified by pointing the reverse proxy at a dummy Java http server -- proxy connects, no data comes through)
This was already fixed (by Doug MacEachern) for 2.0.36. Thanks for using Apache!
*** Bug 8751 has been marked as a duplicate of this bug. ***