No fast forward with external subtitles enabled

[alf]

Hello

Situation:
- UMS installed on Windows XP PC computer.
- Movie on PC hard drive (formats MP4, AVI or MKV with no subtitles embedded in the movie container)
- External subtitle in SRT format.
- Movie viewed on TV Toshiba 40RL938 via UMS.

What happens:
- If the subtitles are disabled in UMS, the movie can be fast forwarded on the TV
- If the subtitles are enabled, the subtitles are seen on the TV but it is not possible to fast forward (or fast reverse): message on the TV indicating that the system is busy.
The behavior is the same on HD movies 1080 and low resolution movies 480.
The behavior is the same if I choose a low CPU and low quality transcoding in UMS.

UMS logs were done with and without subtitles (disabled in UMS transcoding settings).
The debug files are attached.
I copied the debug log and added comments corresponding to the actions done on the TV to show when the actions were done.
The comment lines in the logs start with TAB #.
These commented logs have been appended to the corresponding debug file archives.

The trials were done with the same movie located at the same location in the computer.
The SRT subtitle file, named as the movie, was located in the movie folder.

For each trial (with and without subtitles), I duplicated the operations logged:
• Connect TV to UMS server
• Navigate to movie folder
• Play movie
• Try fast forward 2 times (no success when subtitles enabled, success when subtitles disabled)
• Pause the movie
These operations are described in the comments inserted in the commented log file.

The movie properties are below:

General
Format : AVI
Format/Info : Audio Video Interleave
File size : 1.38 GiB
Duration : 1h 52mn
Overall bit rate : 1 768 Kbps
Writing application : VirtualDubMod 1.5.10.2 (build 2540/release)
Writing library : VirtualDubMod build 2540/release

Video
ID : 0
Format : MPEG-4 Visual
Format profile : Advanced Simple@L5
Format settings, BVOP : 2
Format settings, QPel : No
Format settings, GMC : No warppoints
Format settings, Matrix : Default (H.263)
Muxing mode : Packed bitstream
Codec ID : XVID
Codec ID/Hint : XviD
Duration : 1h 52mn
Bit rate : 1 694 Kbps
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 5:4
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.163
Stream size : 1.33 GiB (96%)
Writing library : XviD 1.0.1 (UTC 2004-06-05)

Audio
ID : 1
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Codec ID : 55
Codec ID/Hint : MP3
Duration : 1h 52mn
Bit rate mode : Constant
Bit rate : 64.0 Kbps
Channel(s) : 1 channel
Sampling rate : 44.1 KHz
Compression mode : Lossy
Stream size : 51.3 MiB (4%)
Alignment : Split accross interleaves
Interleave, duration : 40 ms (1.00 video frame)


Please let me know if you need any more info.

Thanks and regards