Comment 4 for bug 521269

Looks like the issue was in mythweb.postinst

Mythweb Authentication was set to true (when in non-interactive mode). This caused postinst to pull in new user/pass. Since we don't store user/pass in plaintext (it gets cleared from conf file), in non-interactive mode user/pass were set to "". Fixed this by changing Mythweb Authentication from always true to "" in non-interactive mode. This allows postinst to not touch the current settings for authentication.

I also noticed a mythweb only setting that was the same. I changed that as well.

I've pushed the changes to fixes and trunk, so I would expect this to be fixed in the next mythplugins build.