PS3, WMP11 Sharing, and file extensions?

[MozartMan]

PS3, WMP11 Sharing, and file extensions?

I can play files with following extensions on my PS3:

.mpg
.m2t
.m2ts
.mp4

from any external media and internal HDD using XMB.

Today I set up WMP11 sharing. It works fine, I can stream videos from my PC, but the thing is that PS3 only sees files with .MPG extension.

Is this suppose to be that way?
Is this WMP11 problem?
Is this PS3 problem?
Am I missing something?

TIA