With the DM7025, you can add a timer through the TV by selecting the ‘info’ button when watching a programme. Once this is stored, if you go to the web server, and try to edit it, you get the error message: “Please only use the characters …. in the name and description field”. You get this message even if the name & description field appear to have valid characters.
This appears to be due to the add timer mechanism through the TV puts invalid characters into the recording entry - these characters look like spaces in the web edit page, but are not actually spaces.
I suspect that these characters are unicode control characters.
The answer, therefore, is to replace anything that ‘look like a space’ with a space.