I have been constantly updating my Oscam to the latest version which are being released 2-3 times a day every day, with the hope that it cures the 28.2 HD channel freezing problem, which it didn't until I came across a collection of plugins called "All_emu_plugin_Alien BY Traian.zip"
I extracted the oscam plugin from this zip and installed it and now all the HD channels work without any problems.
I would suggest anybody having problems with the HD freezing to try and use this version of the Oscam... I can't find the version no but I am more than happy to attach it to this thread if need be.
We are talking about the enigma2 side not the spark, spark side is glitch free with oscam it might be your server or satellite cable quality.