Posible bug?

I'm new, so i may be missing something, but i was pulling my hair out today trying to figure out why formulas that used "false" didn't produce consistent results. They possibly worked one time (?), but then failed after that.

For example, i had one expression in Display field only using false, that worked first time (i think), but didn't work afterwards. It was in the form: Field A != Something and Field B = false.

It seemed to be right, but it just wasn't working (apart from maybe a first time). Then i tried the exression in the form Field A != Something and Field B != true - that worked like a charm.

I had another formula on a field using "false" and it gave inconsistent results, depending on whether the part of the formula calling false was involved. Once i also switched that to != true it worked properly.