Sorry, I don't see a way to reproduce that one.
Try to enable debugging (in the plugin settings) and enter "spy.core,asyn.http" (without the quotes) in the Debug Modules field. Maybe the extra output will shake some helpful evidence loose.
I do have occasionally had users with mysterious UI errors like that which, mysteriously, disappeared when they deleted and recreated the device. Can't say that will help; just saying it helped someone, sometime.
Cheers
-- perry