I have a drawing with visretain set to 1 which has an XREF attached. When I freeze any layer, save, then reopen the drawing that layer is still frozen as you would expect. When I freeze a layer with a name consisting of the @ character, save and then reopen it that layer is no longer frozen. The drawings are supplied by an external source so I cannot just rename the layer as I will receive updates during the course of the project. Any ideas of how I can get round this? Is this a standard system function or is it a software error?
Communicate with your supplier and explain that non-alphanumeric characters is layer names cause problems. That's really the bottom line -- limit layer names to alpha numerics, hyphens, and underscores, and things work. Add ampersands, 'ats', colons, tildes, etc and things will start to fail .
As I said in my original post, I realise that the @ character is the cause of the problem, however as I also mentioned these drawings were created by an external company and we cannot change them. I cannot control the supplier of the drawings and was hoping for a workaround which I see now is not going to be possible.