>Ok, that's what I'm going to do because I didn't found anything neither in MSDN nor over the internet. But (as always) leak of information may raise incompatibility problems on some systems where "unused" bits are used in unknown way.
I think, as long as you only read the data you don't have to worry about incompatibility. Just make sure you read the right bytes. However it is a good reason to take precaution
Herman