I've observed a serious problem when I turn on my iPad and do some internet stuff.
After that, I start having serious DHCP problems with my Time Machine Wifi. I use a lot of vmWare virtual machines to work and never had happened until I use the iPad.
After an iPad use, some virtual machines start to complain about IP conflicts...
It seems iPad does not send a "DCHP IP disconnection" (or wahtever command is) when switching off and on swith on it simply tries to use the old IP instead of asking a new one via DHCP...
I know it is the iPad network problem most iPads have, but with at least they must had tested with a Time Machine and it seems they don't. Very poor for Apple.