i noticed yesterday in defragger when i highlighted a fragmented file to see what blocks it was in it was always marking first one but the file it not even listed in it
even after fragmenting drive then updating Microsoft security signatures again same thing happens
the cluster block usage and the file representation is not an exact match up.
sometimes selecting a file and seeing its blocks or selecting a block and seeing its files gives mixed results. treat it more like a guide than an exact science.
for example, there is some sort of threshold DF uses, say a file has a frag in one block, it may not show that until it has, say, 3 frags in that block. (that's just an example but it seems to fit with what I've experienced DF doing)
is this problem preventing you from using DF? (just asking)
what version of DF are you running?
if so, do you remember the previous version it didn't happen with? (you say you hadn't seen it before)
personally I think it's always done it (what I call the rounding error) but if you can't use the version try reverting back to an earlier version until DF behaves the way you'd prefer.
previous versions can be found at FileHippo, as one example. Just be wary of 'fake' download buttons.
well, tell DEV to get on the stick! I'm sure its an easy fix. I submitted this as a bug too, without realizing the bug was found 3 months ago and never fixed.