I was wondering about this as I was trying to convert some WMV files that I downloaded (legally purchased Anime files thank you very much), and ran accross the usual mixture of bad files some of which were fixable some of which weren't. Now, I'm not looking for how to fix them, I just contacted the company about bad files ( Advantage of legal stuff). But it does seem like every group of ASF/WMV files has at least a few bad ones, some of which are fixable and some of which aren't. This is not something I see in any other format. I'm not worried about the rare exception, because that can always happen, but seems like the rate for ASF/WMV bad files is around 2 in 10 (or even higher). Other formats, MPEG, DiVX, regular AVI, RM, MOV, don't seem to have that problem and when they do they are almost 100% fixable. What's the deal?

Theories are:

1) It's M$ and they don't let "good programmers" write anything for the format.

2) It's a lousy format so folks who use it don't know what they are doing (possibly made worse by #1 above). This is my favorite.

3) It's an inherently problematic format and there will always be unreadable files.

4) It's a format that is easily corrupted by lost bits of data and since most of the format is from files on the internet, there are always lost bits they will always have issues.

5) Something I've missed?

Theories or facts anyone.