Somehow I remember previous versions of Fireworks having a different default for pasted text, than what currently happens in CS5. When I select text, copy, select the existing text that I want to replace, and paste, the attributes displayed are from the text that I pasted from, not the text I pasted to. It seems that it should be the other way around.
I select TEXT A which is red, normal, with crisp anti-aliasing and copy it.
I then select TEXT B which is blue, bold, with strong anti-aliasing and past TEXT A over it.
What I expected to end up with is TEXT A with the attributes of TEXT B, but instead I get TEXT A with the original TEXT A attributes (and no, I'm not using Paste Attributes).
Is there a work around for this? Preferences don't have a setting which would give one the choice. Come to think of it, there are a LOT of preferences I'd like to see added, like defaulting to pixels for leading rather than percent, and inches rather than centimeters for resolution, etc.
A lot of things have changed with text handling in Fireworks. When the Adobe type engine was added, text behaved much differently than it did with the old Macromedia text engine. Perhaps that was when the behaviour you describe changed, but I honestly can't remember. The current behaviour is the same in both Photoshop and Illustrator.
All the attributes of copied text are retained where possible. Might have had something to do with maintaining text fidelity when copying text from Photoshop or Illustrator.