I've been having issues with losing wireless internet connectivity when the only wired desktop on the system enters sleep mode. This happens with any device that is connected to the wireless modem/router. If I go to the desktop and move the mouse enough exit sleep mode, the wireless connects again and all is good. There is never an issue if the desktop is shut down. Any suggestions would be appreciated.
That's a weird one.
What happens if you unplug the sleeping computer from Ethernet?
What kind of computer is the "sleeper?" Windows? MAC? Linux?
If you hibernate the computer, what happens?
Is the computer plugged directly into your router? If so, what do the status lights for the computer's Ethernet port on the router report? Do the lights change when the computer is on or off?
If the computer isn't plugged directly into the router, what is it connected to? What does that device's status lights report? Try removing this device and see if anything changes.
When wireless isn't working, exactly what is happening on the other devices? Do they see your network? What do they report about your network?