iPad keeps disconnecting from ad-hoc networks
i'm having the same problem, i use my laptop as internet server, all other computer is connected to the network and have internet access, when i use my tablet and after a while it losses the internet access even though it's still connected to the network (only skype keeps working, no browsing and no facebook).

to fix it you need to do the following:

right click on Computer >> Properties >> Device Manager >> network adapters >> right click on Ethernet Controller >> Properties >> Power Management >> uncheck the box "Allow the computer to turn off this device to save power".

it should work fine now