Recent versions of Freecell Solver pass the moves from the initial position
to the final solution to the layer above them.
The stack -> stack moves are being outputted with the number of cards
that are moved.
Freecell Pro, on the other hand, used to ignore the number of cards and
expected such moves to comply with what the original Microsoft Freecell
would do in that case.
This caused problems in playback of a large percentage of the games in
its integration with Freecell Solver.
A post I made to the mailing list about it sparked a very big flamewar that diverted
to cover related topics.
Usually the only things that happen there is that I announce new releases or
ask the members questions and no-one or few people reply.
Eventually, Adrian Ettlinger (an FC-Pro hacker) have extended Freecell Pro
to make use of an optional number of cards to move argument. This made
playback of Freecell Solver solutions perfectly smooth.