Are the DVD Rips "raw rips" (direct MPEG-2 rips without transcoding them) or have they been compressed and transcoded to MPEG-4 of some variety (like x264)? What filters are being used for playback? If you aren't sure, you can find this in MC by right clicking in the Playback window and choosing DirectShow Filters --> Copy graph info to clipboard and then pasting it here.
This is mine for a "raw" DVD rip (directly out of DVD Fab with no transcoding and not encased in a MKV or anything else):
Filter Graph Info:
Filter 'Default DirectSound Device'
CLSID: {79376820-07D0-11CF-A24D-0020AFD79767}
Host: C:\WINDOWS\system32\quartz.dll
Input Pin 'Audio Input pin (rendered)'
Connected to pin 'Out' of filter 'ffdshow Audio Decoder'
Major type MEDIATYPE_Audio Sub type MEDIASUBTYPE_PCM, Format type FORMAT_WaveFormatEx
Filter 'Video Renderer'
CLSID: {70E102B0-5556-11CE-97C0-00AA0055595A}
Host: C:\WINDOWS\system32\quartz.dll
Input Pin 'Input'
Connected to pin 'Output' of filter 'Overlay Mixer'
Major type MEDIATYPE_Video Sub type MEDIASUBTYPE_Overlay, Format type FORMAT_VideoInfo
Filter 'ffdshow Audio Decoder'
CLSID: {0F40E1E5-4F79-4988-B1A9-CC98794E6B55}
Host: C:\Program Files\Combined Community Codec Pack\Filters\FFDShow\ffdshow.ax
Output Pin 'Out'
Connected to pin 'Audio Input pin (rendered)' of filter 'Default DirectSound Device'
Major type MEDIATYPE_Audio Sub type MEDIASUBTYPE_PCM, Format type FORMAT_WaveFormatEx
Input Pin 'In'
Connected to pin 'AC3' of filter 'DVD Navigator'
Major type MEDIATYPE_DVD_ENCRYPTED_PACK Sub type MEDIASUBTYPE_DOLBY_AC3, Format type FORMAT_WaveFormatEx
Filter 'Overlay Mixer'
CLSID: {CD8743A1-3736-11D0-9E69-00C04FD7C15B}
Host: C:\WINDOWS\system32\qdvd.dll
Input Pin 'Input0'
Connected to pin 'Output' of filter 'MPC - MPEG-2 Video Decoder (Gabest)'
Major type MEDIATYPE_Video Sub type MEDIASUBTYPE_YV12, Format type FORMAT_VideoInfo2
Input Pin 'Input2'
Connected to pin 'XForm Out' of filter 'Line 21 Decoder'
Major type MEDIATYPE_Video Sub type MEDIASUBTYPE_RGB32, Format type FORMAT_VideoInfo
Input Pin 'Input3'
Output Pin 'Output'
Connected to pin 'Input' of filter 'Video Renderer'
Major type MEDIATYPE_Video Sub type MEDIASUBTYPE_Overlay, Format type FORMAT_VideoInfo
Filter 'Line 21 Decoder'
CLSID: {6E8D4A20-310C-11D0-B79A-00AA003767A7}
Host: C:\WINDOWS\system32\qdvd.dll
Input Pin 'XForm In'
Connected to pin '~CC' of filter 'MPC - MPEG-2 Video Decoder (Gabest)'
Major type MEDIATYPE_AUXLine21Data Sub type MEDIASUBTYPE_Line21_GOPPacket, Format type FORMAT_None
Output Pin 'XForm Out'
Connected to pin 'Input2' of filter 'Overlay Mixer'
Major type MEDIATYPE_Video Sub type MEDIASUBTYPE_RGB32, Format type FORMAT_VideoInfo
Filter 'MPC - MPEG-2 Video Decoder (Gabest)'
CLSID: {39F498AF-1A09-4275-B193-673B0BA3D478}
Host: C:\Program Files\Combined Community Codec Pack\Filters\Mpeg2DecFilter.ax
Input Pin 'Video'
Connected to pin 'Video' of filter 'DVD Navigator'
Major type MEDIATYPE_DVD_ENCRYPTED_PACK Sub type MEDIASUBTYPE_MPEG2_VIDEO, Format type FORMAT_MPEG2_VIDEO
Output Pin 'Output'
Connected to pin 'Input0' of filter 'Overlay Mixer'
Major type MEDIATYPE_Video Sub type MEDIASUBTYPE_YV12, Format type FORMAT_VideoInfo2
Input Pin 'SubPicture'
Connected to pin 'SubPicture' of filter 'DVD Navigator'
Major type MEDIATYPE_DVD_ENCRYPTED_PACK Sub type MEDIASUBTYPE_DVD_SUBPICTURE, Format type FORMAT_MPEG2_VIDEO
Output Pin '~CC'
Connected to pin 'XForm In' of filter 'Line 21 Decoder'
Major type MEDIATYPE_AUXLine21Data Sub type MEDIASUBTYPE_Line21_GOPPacket, Format type FORMAT_None
Filter 'DVD Navigator'
CLSID: {9B8C4620-2C1A-11D0-8493-00A02438AD48}
Host: C:\WINDOWS\system32\qdvd.dll
Output Pin 'Video'
Connected to pin 'Video' of filter 'MPC - MPEG-2 Video Decoder (Gabest)'
Major type MEDIATYPE_DVD_ENCRYPTED_PACK Sub type MEDIASUBTYPE_MPEG2_VIDEO, Format type FORMAT_MPEG2_VIDEO
Output Pin 'AC3'
Connected to pin 'In' of filter 'ffdshow Audio Decoder'
Major type MEDIATYPE_DVD_ENCRYPTED_PACK Sub type MEDIASUBTYPE_DOLBY_AC3, Format type FORMAT_WaveFormatEx
Output Pin 'SubPicture'
Connected to pin 'SubPicture' of filter 'MPC - MPEG-2 Video Decoder (Gabest)'
Major type MEDIATYPE_DVD_ENCRYPTED_PACK Sub type MEDIASUBTYPE_DVD_SUBPICTURE, Format type FORMAT_MPEG2_VIDEO
My (completely uneducated) guess is that you are hitting the limits of that onboard video card, but I don't know. It totally could be a bad/broken/stupid filter. Most (if not all) of the processing should be handled by the CPU, not by the GPU, so in theory the GPU shouldn't matter unless you're trying to use it to do Deinterlacing or something else in the Video card drivers.