item error reporting

[cadbury]

when adding a UserParameter, and an item to monitor it,
if the agent return an error, the error message
"Not supported by agent" appear in the items config panel
but then when the UserParameter is fixed and doesn't return any error,
the error message stay.
is it a normal behavior?
I think the error message should disapear if no error is returned then

[Alexei]

To be fixed!