Everytime I want to manually perform an "program update" (I select this option always to update my definitions), my gadgets disappear from desktop and I have to reenable them. This does not happen when I try to to perform an 'Engine and virus definitons update'
I'm runing Avast! Free 6.0.1367 (latest version) on Windows 7 Professional SP1 x86
Also, I mention that I don't have the Avast! gadget installed.