I'm running OSX 10.6.8 previously upgraded from 10.5. I also started with CS4 and upgraded to CS5. I do not remember in what order sw where changed if that is of importance. I also remember that the upgrade from CS4 to CS5 left alot of CS4 stuff behind that I later uninstalled to free disk space.
I have had this problem some time but I haven't been i n a hurry to solve the problem until now. The last event I remember related to this was that in the middle of stressed work I rejected an update of the AIR sw with the believe that the update will be available later.
As soon as I start help in say DW I get the message as described above and also the instruction to 'Try re-installing or contacting the publisher for assistance' regarding AIR. What does that mean? As far as I can see the Adobe AIR is not part of the CS5 so it is not covered in the general installation app. There are separate install and unistall apps for AIR and when trying them out the install asks for a package that I have no clue of what it is and the unistall alerts that if I continue other dependent applications will not work. I aborted both tries. I cannot affort a production stop in using the DW & FW at this time.
Finally, I'm not using Adobe AIR as far as I know or mabe I am without knowing it when using DW. It probably just came with CS4 or 5. The help complains and points out AIR as damaged as soon as help starts. The applications in CS5 are running fine as far as I can se.