[mythtv] Problem changing channels after upgrade to 0.25

[Bob K Mertz]

I recently upgraded my Mythbuntu system to 11.10 and just last night I 
decided to upgrade to the 0.25 branch using mythbuntu-repos (see below 
for more information on versions, etc).  Since the upgrade I have not 
been able to change channels from one tuner to the same tuner which is 
connected to a Dish Network receiver.  When I attempt to do so the 
system hangs for about 10-30 seconds and then usually returns back to 
the main menu with "Error opening jump program file".  This happens 
every single time that I switch a channel from dish network to another 
dish network channel.  I also have 2 tuners connected to analog cable 
and if I first switch to a channel from that source and then switch back 
to a dish network channel everything works fine.  In order to rule out a 
delay in signal lock because of the receiver needing to change channels 
I disabled the change channel script so that the receiver was constantly 
broadcasting out of the composite display and this made no difference.

I have been doing a lot of searching and googling and I'm wondering if 
this is related to this change: 
https://github.com/MythTV/mythtv/commit/4e8d935

 From what I have been seeing there have been people that experienced 
this issue with earlier versions of myth but never with 0.24 with the 
exception of 0.24-fixes.  My assumption is that this change was back 
ported to 0.24.  I also saw that in 0.22 the ringbuffer was changed to 
10 seconds rather than the 2 seconds.  My thoughts are that prior to 
upgrading to 0.25 when changing a channel my system was taking longer 
than 2 seconds to start writing the mpg file to disk but since the 
timeout was 10 seconds this wasn't an issue but now it is becoming an 
issue.  I will admit I'm not a developer so I may be way off base but I 
wanted to get some feedback on this issue before filing a bug report (if 
that becomes required), etc.

System information:
2 front ends, 1 backend
Backend machine is a dual CPU AMD Opteron system with 8GB of RAM 
(running 32bit) and is running Mythbuntu 11.10.  Machine has 3 PCI 
PVR-150 tuner cards installed (one is connected to a dish network 
receiver and 2 others connected to analog cable).  Hard drives are all 
on a 3ware RAID controller with multiple RAID arrays configured (2 are 
recordings directories and each of those are on their own dedicated 
array).  Both front end machines are Dell Pentium 4 systems.  One has a 
Nvidia GeForce 6200 and the other has an older Nvidia card.  Both front 
end machines are connected via 10/100 ethernet.

I can gather up applicable log files but I wanted to get an initial 
opinion from the developer community and possibly get better direction 
as to which log files I need to pay attention to.

Backend version:
Please attach all output as a file in bug reports.
MythTV Version : v0.25pre-4084-g867d96a
MythTV Branch : master
Network Protocol : 71
Library API : 0.25.20120120-1
QT Version : 4.7.4
Options compiled in:
  linux profile use_hidesyms using_alsa using_oss using_pulse 
using_pulseoutput using_backend using_bindings_perl 
using_bindings_python using_bindings_php using_crystalhd using_dvb 
using_firewire using_frontend using_hdhomerun using_ceton using_hdpvr 
using_iptv using_ivtv using_joystick_menu using_lirc using_mheg 
using_opengl_video using_qtwebkit using_qtscript using_qtdbus using_v4l2 
using_x11 using_xrandr using_xv using_bindings_perl 
using_bindings_python using_bindings_php using_mythtranscode 
using_opengl using_vaapi using_vdpau using_ffmpeg_threads using_live 
using_mheg

Frontend version:
Please attach all output as a file in bug reports.
MythTV Version : v0.25pre-4084-g867d96a
MythTV Branch : master
Network Protocol : 71
Library API : 0.25.20120120-1
QT Version : 4.7.4
Options compiled in:
  linux profile use_hidesyms using_alsa using_oss using_pulse 
using_pulseoutput using_backend using_bindings_perl 
using_bindings_python using_bindings_php using_crystalhd using_dvb 
using_firewire using_frontend using_hdhomerun using_ceton using_hdpvr 
using_iptv using_ivtv using_joystick_menu using_lirc using_mheg 
using_opengl_video using_qtwebkit using_qtscript using_qtdbus using_v4l2 
using_x11 using_xrandr using_xv using_bindings_perl 
using_bindings_python using_bindings_php using_mythtranscode 
using_opengl using_vaapi using_vdpau using_ffmpeg_threads using_live 
using_mheg