I think there’s a good chance that your CD0 DOSDriver got overwritten with the default from 3.2. Check SYS:OLD - the Installer may have backed it up. Otherwise you’ll need to generate a new one. I think Asim has a tool for that; if not you’ll need to make one manually using the version on the Asim install disk as a template. But remember that Asim keeps its DOSDrivers in Storage rather than Devs.
Also check user-startup to make sure your Asim mount commands are still there. They should be; I don’t think 3.2 does anything to user-startup.