Mpeg2 to Mpeg1 problem

[tonemgub]

Just some info on the file I'm wanting to convert. It is MPEG2 and fps is 29.976. I've been having trouble with a MPEG2 (audio+video). It plays perfect and on sync in Media Player Classic and PowerDVD but it is choppy in VLC and Windows Media Player.

Here is my problem.
I am wanting to convert that to an MPEG1 (just video). My problem is that when I go to encode it with TMPGENC the resulting file's video plays too quickly (MPC reports it is playing at 29.976 but it looks faster). Same thing happens when I encode using CCE Trial. It even does it when I just serve this Avisynth script:

DirectShowSource("C:\movies\original-MPEG2.mpg")
ConvertToYUY2()

How can I convert this troublesome MPEG2 to MPEG1?[/code]

[tonemgub]

Nobody has had this problem?