I lose connection between my slingbox av and my linksys router after about 5 minutes. I can reset it by reseting the power on the linksys and it'll come back up and work again for about 5 minutes before dropping. It has worked for years until now and I haven't added any hardware/software that I'm aware of.
This is wireless ? See if you can detect strong neighbouring wifi network and move to a channel 5 stops away from strongest. If you live in a terrace property or apartment -- may also be interference from cordless phone, video sender etc.