Problem skipping forward and backward in recorded TV

Skipping forward and backward when watching recorded TV programs is not working correctly. This is true for both small and big skip steps. For example, when I try to skip forward 5 minutes, it may skip forward anywhere from a few seconds to a few minutes. However, when I watch the program as a video, skipping works perfectly.

Here is a portion of the log when a big step forward (5 min) is requested while playing back a recorded TV program. Note that although the log says the seeking was a success, it actually wasn’t.

Code:
21:54:30.282 T:140735132622848   DEBUG: Keyboard: scancode: 0x7e, sym: 0x0111, unicode: 0xf700, modifier: 0x0
21:54:30.414 T:140735132622848   DEBUG: OnKey: up (0xf080) pressed, action is ChapterOrBigStepForward
21:54:30.419 T:123145310429184   DEBUG: CVideoPlayer::SetCaching - caching state 2
21:54:30.419 T:123145310429184   DEBUG: CDVDClock::SetSpeedAdjust - adjusted:0.000000
21:54:30.419 T:123145310429184   DEBUG: demuxer seek to: 320691.000000
21:54:30.419 T:123145310429184   DEBUG: AddOnLog: PVR WMC Client: Socket::GetVector> Send request "StreamFileSize|0"
21:54:30.432 T:123145323921408   DEBUG: CDVDAudio::Pause - pausing audio stream
21:54:30.446 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] SPS unavailable in decode_picture_timing
21:54:30.446 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] non-existing PPS 0 referenced
21:54:30.446 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] SPS unavailable in decode_picture_timing
21:54:30.446 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] non-existing PPS 0 referenced
21:54:30.446 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] SPS unavailable in decode_picture_timing
21:54:30.446 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] non-existing PPS 0 referenced
21:54:30.446 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] SPS unavailable in decode_picture_timing
21:54:30.446 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] non-existing PPS 0 referenced
21:54:30.453 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] SPS unavailable in decode_picture_timing
21:54:30.453 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] non-existing PPS 0 referenced
21:54:30.453 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] SPS unavailable in decode_picture_timing
21:54:30.453 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] non-existing PPS 0 referenced
21:54:30.453 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] SPS unavailable in decode_picture_timing
21:54:30.453 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] non-existing PPS 0 referenced
21:54:30.453 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] SPS unavailable in decode_picture_timing
21:54:30.453 T:123145310429184   ERROR: ffmpeg[7000007BE000]: [NULL] non-existing PPS 0 referenced
21:54:30.454 T:123145310429184   DEBUG: SeekTime - seek ended up on time 294240
21:54:30.454 T:123145310429184   DEBUG: demuxer seek to: 320691.000000, success
21:54:30.454 T:123145310429184   DEBUG: CVideoPlayer::FlushBuffers - flushing buffers
21:54:30.463 T:123145323921408   DEBUG: CDVDAudio::Flush - flush audio stream
21:54:30.464 T:123145323921408   DEBUG: CDVDAudio::Pause - pausing audio stream
21:54:30.468 T:123145317482496   DEBUG: CVideoPlayerVideo - CDVDMsg::GENERAL_SYNCHRONIZE
21:54:30.468 T:123145323921408   DEBUG: CVideoPlayerAudio - CDVDMsg::GENERAL_SYNCHRONIZE

Here is a portion of the log when a big step forward is requested while watching the same program being played back as a video. This seek really was successful, even though it says “unknown position after seek.”

Code:
22:06:04.675 T:140735132622848   DEBUG: Keyboard: scancode: 0x7e, sym: 0x0111, unicode: 0xf700, modifier: 0x0
22:06:04.742 T:140735132622848   DEBUG: OnKey: up (0xf080) pressed, action is ChapterOrBigStepForward
22:06:04.746 T:123145307746304   DEBUG: CVideoPlayer::SetCaching - caching state 2
22:06:04.746 T:123145307746304   DEBUG: CDVDClock::SetSpeedAdjust - adjusted:0.000000
22:06:04.746 T:123145307746304   DEBUG: demuxer seek to: 301420.000000
22:06:04.746 T:123145307746304   DEBUG: SeekTime - unknown position after seek
22:06:04.746 T:123145307746304   DEBUG: demuxer seek to: 301420.000000, success
22:06:04.746 T:123145307746304   DEBUG: CVideoPlayer::FlushBuffers - flushing buffers
22:06:04.757 T:123145334480896   DEBUG: CDVDAudio::Pause - pausing audio stream
22:06:04.768 T:123145334480896   DEBUG: CDVDAudio::Flush - flush audio stream
22:06:04.768 T:123145334480896   DEBUG: CDVDAudio::Pause - pausing audio stream
22:06:04.797 T:123145324994560   DEBUG: CVideoPlayerVideo - CDVDMsg::GENERAL_SYNCHRONIZE
22:06:04.797 T:123145334480896   DEBUG: CVideoPlayerAudio - CDVDMsg::GENERAL_SYNCHRONIZE

Any ideas about what is going on here?