Explorer cannot show AVI file Duration?

[Terry Pinnell]

Using XP Home, I have a folder of WMV and AVI files. The WMV files
have an entry in the Duration column, but not the AVI files. Why is
that please?

 

[V Green]

Must be some kind that Explorer "chooses"
not to understand.

The .AVI's generated by my Winnov capture card
and DivX .AVI's display correctly in the Duration
column here.