[mythtv] Expectation of services compatibility .27 to .28?

[BP]

Before I start writing up a bug, I wanted to ask what the expectation is 
for compatibility with .28 for third party clients written to use the 
external service api in .27.  I know that it is expected that the 
frontend and backend are kept in sync.  I thought that the services were 
meant to be more long lived.  Please let me know if that is off base.

Here's what I'm seeing.

First, 
03c4c94dc6f900cabee1fde4f21c49b941d13940#diff-8f280c0fe6f6352d92240ebe6acec785 
looks to have broken /Content/GetRecording (possibly others like Delete 
that I have not tested).  Per 
www.mythtv.org/wiki/Content_Service#GetRecording , it looks like the 
intent was to add an optional param of RecordedId to simplify requests. 
  What happens is if I make a request with the legacy format of 
BackendServerIP:6544/Content/GetRecording?ChanId=34736&StartTime=2011-08-29T18:59:00 
, the server returns a 500 error.  I can only make the request work if 
RecordedId is passed as the first param.  If it is added as the third, 
it still returns a 500.  It does not matter if I include ChanId and/or 
StartTime params so long as RecordedId is first (or the only).  This can 
be tested with wget.

I successfully reverted that commit to get past the 500 issues.  I still 
had problems with video not playing, however.  I narrowed that down to 
7bf6bb1364803931f5975d3a9c396d6dcb2d0a47#diff-c8e615e3ae736a710d8c1bb06fc493bb 
which changed mime types to work better with all upnp devices.  The 
change from video/mpeg to video/mp2p is breaking service clients as 
well.  Reverting that change restored functionality for me.