Hello,
I just stumble on a funny bug, I think.
I've tried to filter card-pool (with F3 key) all "artifact creature" from Aliance. No cards were displayed (there are artifact creatures in Aliance). If I replace "Aliance" with a more recent set (7e ed. for instance) cards are displayed.
I did not check every set - so I'm unable to tell "ok, it is working from this set till RTR" - nor if the filter does actually work well with apparent working sets or is it just partially working (i.e. if cards are displayed I suppose all the cards are displayed). I also didn't try to filter collection, nor to filter the bottom screen (shift-F3).
I tried with Aliance, Revised, The Dark, Ice Age and no artifact creature is displayed. If I choose "artifact" instead, then I got all artifacts but artifact creatures. In short, I am unable to filter to just see artifact creatures from old sets.
If I filter from the column header, it does work well. So I have a workaround.
I'm using 3.5 portable.
Regards.