"This is a new issue then."
No, same issue. There was a flash update back in June and it seems your just getting word from some of your clients that just updated.
"Does easypano know about this new issue with the latest Flash player?"
Yes, I pointed you to the links they provided. Be sure to clear your cache!
HERE is a link that covers the flash update disscusion but in the end will point you to download the .swf from easypano.
"I have no source files for some of the older jobs of mine."
Easypano provided an updated .swf to correct the issues of the flash update. In the end it is up to the end user to keep solid, dependable backups of the project files.
As for "legel" issues, I'll refer you to contact easypano with that.
I know and understand the frustration of clients calling informing their tours are not working. This issue though has been discussed with the links I provided to you. There was a flash update back in June that affected more .swf files than just those of easypano. Not sure what else I can tell ya?