Then I don't understand why there is more than one format change between major releases. Fedora 7 ships beta2 AFAIK, other distros might ship rc1. If not even a _Release Candidate_ is worth it to maintain compatibility, then there is no need to care for any intermediate svn version.
Here is the whole story: 1. we only provide export to 1.4.x and 1.3.x from 1.5.x. 2. Only 1.5.x can enter unrecognizable listings parameters. 3. If a user is using RC1, he can not read 1.5.x file, so the file has to be exported to 1.4.x, in which listings will be converted to ERT. And he will have no problem. The only case an error will happen is when someone explicitly, I guess running lyx2lyx from command line, convert a 1.5.x file with unrecognizable listings parameter to RC1 format, and use RC1 to open it. Because this is not something a normal user is supposed to do, we decided to ignore this case. Cheers, Bo
