comes with software, unusual for mice but I assume this is a powerhouse mouse with special features.
Did you install that software?
Details here, (and click on Specifications); http://www.logitech.com/en-ca/mice-pointers/mice/devices/optical-gaming-mouse-g400
If you did and the problem still persists, then have you tried another USB port? If you are using a USB port at the front of the machine, try connecting it to one at the back.
WinXp Home, I have an old Dell Dimension 4500, 2002.
I had a Logitech MX 510 or 518, I think it was, and it started acting up, So I got 2 warrantied from them, had one go bad a while ago and never did anything, they sent me 2 G 400's. Well I was using the PS/2 port, the G400's will not work in those they must be used in USB ports according to Logitech. Yep I tried anyway. Because both mice will stay stuck firing or stuck not firing every minute or 2 and or just stop reading if I move fast I think is when it happens in quake 3 arena or quakelive, an then will start working proper in a few seconds. So I tried an older mx310 in the PS/2 port and it just stops reading for a couple seconds every minute or so, but then starts to work after 2 - 4 seconds, I only use the drivers windows installs, How ever with the G400's After they didn't work proper I installed their gaming software for it. I have tried to go into safe mode and uninstall the mice that I seen , it only seen the one currently in use. But that didn't help, any ideas ?