Not seen that before myself.
How full is the storage on the HC and on the LM? From what I can gather to save settings the HC needs to write a whole new "settings" file in it's own memory (for HC settings) or in the LM's memory (for LM settings) and to do that it needs to write the new settings file before it can delete the old settings file. I don't think any error is thrown in this regard when there isn't enough space to write the new settings file first, only when your trying to copy something to memory and it doesn't fit.
If your free space in the HC or LM isn't a lot try deleting a couple of things from the HC's or LM's memory and see if you can then save the new settings.
- Tim