FWIW, these are the possible settings that affect PVR in the advanced settings xml:
<pvr>
<timecorrection>0</timecorrection> <!-- Correct all times (epg tags, timer tags, recording tags) by this amount of minutes. -->
<infotoggleinterval>3000</infotoggleinterval> <!-- If there is more than one pvr gui info item available (e.g. multiple recordings active at the same time), use this toggle delay in milliseconds. -->
<minvideocachelevel>5</minvideocachelevel> <!-- Cache up to this level in the video buffer buffer before resuming playback if the buffers run dry. -->
<minaudiocachelevel>10</minaudiocachelevel> <!-- Cache up to this level in the audio buffer before resuming playback if the buffers run dry. -->
<cacheindvdplayer>true</cacheindvdplayer> <!-- Cache PVR stream in DVDPlayer. -->
<channeliconsautoscan>true</channeliconsautoscan> <!-- Automatically scan user defined folder for channel icons when loading internal channel groups. -->
<autoscaniconsuserset>false</autoscaniconsuserset> <!-- Mark channel icons populated by auto scan as "user set". -->
<numericchannelswitchtimeout>1000</numericchannelswitchtimeout> <!-- Time in ms before the numeric dialog auto closes when confirmchannelswitch is disabled. -->
</pvr>
i am using
<minvideocachelevel>60</minvideocachelevel>
<minaudiocachelevel>60</minaudiocachelevel>
and have help a lot in minimizing the freezes, although, it will take longer to change/load channels, it will run more smoothly.