[ViX_Misc] Sleep Timer Function on Vix images

[birdman]

I think @birdman tried to fix this some time ago (like 18 months ago!) but it doesn't quite seem to work as intended.

That was a separate issue. For that, if a repeating timer were deferred it remembered its original time-slot and used that for the next occurrence when it finally ran. As far as I'm aware that is till OK (it was working when I wrote the code...).