Cannot access TeamViewer when Mac is "asleep"

[ccontario]

I saw two other threads addressing this issue with no resolution offered, or any useful comments, but I thought I would try again.

TeamViewer shows "offline" when our Mac is asleep, but as soon as move the mouse or touch the keyboard we see that TeamViewer is actually running. It just appears offline when sleeping. Does anyone have any information about this or know of a way to keep TV accessible when a Mac has been put in sleep mode?