Try setting video size to 320x240 (choose "320x240 J River Codec 29.97fps" for "Recording/time-shifting Profile".
Using video compression actually may help, since uncompressed video is large, and may strain your hard disk, unless you have super fast hard drive.
You can create a custom profile based on "320x240 J River Codec 29.97fps" , then you can experiment with different video compressors, or no compressor.