It seems like everytime my system goes into "Sleep" mode my mouse just completely stops working. The strangest part of this is that when I disconnect it and plug it back in, it instantly works again. Happening to anyone else or is it something I did wrong?

Open Device Manager (located in the Control Panel) and scroll down to "Mice and other point devices". Expand and then right-click on your mouse entry and click on Properties > Power Management and place a check next to "Allow this device to wake the computer", then click OK.Carey Frisch

Wasn't quite it but because of your response I solved the issue. Under Power Management it had checked "Allow computer to turn off this device to save power" and that's exactly what it was doing. Thanks for your help Carey!! :)