DVD playback jerks when a subtitle appears

I am having a problem with a Windows 7 media center system I set up. If I am watching a DVD with the subtitles on, whenever a subtitle appears on the screen, the video drops a frame, causing it to appear jerky. If I turn the subtitles off, this problem goes away. It also does not appear with the normal TV-style closed captioning when watching live or recorded TV. Thanks in advance for your help.

Here are the relevant specs for the system:
Intel C2D 2.93gHz
4gb RAM (DDR3, I think)
nVidia 9500gt 1gb videocard (driver 196.84, connected to 1080p HDTV with HDMI)
Windows 7 Pro (of course) with all updates applied

Your system should be able to handle it not problem, there might be a fix, or somewhat of a fix...

Try setting the processes priority to "Real Time", you can do this by right-clicking it under the processes tab in task manager, go to "set priority", Real Time.

I doubt if that will work but it is worth a shot. Also i would recommend a video player like VLC if you do not use that already, I have used it since i knew it existed.

Using another media player isn't really an option, since the system doesn't have a (readily-accessible) keyboard and mouse, and is controlled only by the MCE remote.