Menu Icon disappears

Every so often I seem to lose the Menu Icon, similar to the one that appears to the left of the Nav key. The icon appears on most of the menu screens, Menu, Applications, Tools, Office, etc; to the right of the signal bar usually.
I've tried the Nokia themes and it doesn't appear. I know I've seen it on both the default themes and themes that I've installed. I've tried everthing I know of to get it up (short of Viagra).
I'm on V12 unbranded Euro1 and it's appeared since updating.
Somebody tell me I'm not going crazy and imagined it!
I live in Gloucester, so perhaps I should stop drinking the flood water.