The only "supported" procedure for hot swapping CardBus cards is to use "cardctl eject" before ejecting. I'm also not really surprised that re-inserting before the previous eject has finished is a bad thing. I try to fix bugs with hot ejecting, but it is very hard to make this bullet proof. Hot swap bugs may be timing sensitive, and may only show up on particular hardware/kernel combinations.
Bugs like this will probably remain relatively low priorities. You are of course welcome to try to track them down on your own... but there is a limit to how much attention I can give to them, since they do not affect normal card operation.