Problem with subtitles (1 Viewer)

[lsf3og]

I'm using ffdshow's subtitle engine to display subtitles which worked great so far.
Now i have an mkv with embedded english subs. Additionally i've got an idx/sub-file which contains subs in five languages. I can only display the embedded subs. Only two other subs are shown in the list of available subs, without language specs and when choosing one of them nothing is displayed.
Is this a known problem within MP and/or ffdshow-subs? I didn't find anything on the forum.

MediaPortal Version: 1.2.2
MediaPortal Skin: StreamedMP
Windows Version: Windows 7 Ultimate 32bit
CPU Type: Intel E6750 2x2.67 Ghz
HDD: 1x CRUCIAL 64GB M4 and 2x Samsung 2TB
Memory: 2x 2GB Kingston
Motherboard: Gigabyte EG41MFT-U2H
Video Card: onboard
Video Card Driver: always most recent
Sound Card: onboard
Sound Card AC3:
Sound Card Driver: always most recent
1. TV Card: Terratec Cinergy 2400i DT
1. TV Card Type: DVB-T
1. TV Card Driver: always most recent
2. TV Card:
2. TV Card Type:
2. TV Card Driver:
3. TV Card:
3. TV Card Type:
3. TV Card Driver:
4. TV Card:
4. TV Card Type:
4. TV Card Driver:
MPEG2 Video Codec:
MPEG2 Audio Codec:
h.264 Video Codec:
Satelite/CableTV Provider:
HTPC Case: Silverstone
Cooling: Arctic Cooling
Power Supply: Arctic Cooling
Remote: Toshiba MCE Remote
TV: Phillips
TV - HTPC Connection: HDMI

 

[lsf3og]

No idea anyone?