Here are some additional details
1. ServerWMC is running on a host HTPC running WMC and XBMC.
2. There is no lag when WMC and XBMC are on the same computer
3. From a second computer running XBMC there is no lag when playing recordings saved on the host HTPC
4. The stuttering is pronounced when viewing video remuxed by ServerWMC on the second computer.
I don't remeber this bing an issue when I first set up the second computer so perhaps something in my configuration has changed.
There are some error messages in the ServerWMC log
2014/05/26 21:41:09.263 Convert2ClientPath> error path not resolved:
2014/05/26 21:41:09.264 Convert2ClientPath> inPath:
http://images.windowsmedia.com/tvcards/org/4027_19.jpg
2014/05/26 21:41:09.264 Convert2ClientPath> local recording path: D:\Recorded TV\
2014/05/26 21:41:09.264 Convert2ClientPath> network recording path: smb://serverwmc:*********@BEYONDTV2-PC/Recorded TV
2014/05/26 21:41:09.264 Convert2ClientPath> returning input path unchanged