With WaveLab recorded files, they can renamed. No problem.
Some files are rendered out of Cubase with iXML metadata, it’s not possible to rename these files. I’ve checked the permissions, they’re ok.
In the input field on the info tab for this file, you can type in the new name, click “Änderungen speichern”. After going back to the file and back to the info tab, the name is the old one. The filename on disk is also not changed.