I set mine to a full 7 days. 9999 minutes. I agree its agravating turning off my network printer since it looses a connection when the lease time ends. It would be nice to have static ip address but then again it overides DHCP and you would be have a Server to handle those needs.
If you setup a static address on the router for a client, there is no expiration! This is accomplished using the mac address and assigning it to an ip of you choosing. This option is located on the lan page. You are still using DHCP but the router will always give the same address to that pc when it powers up. The pc will send out a request each time it starts up so any new dns info is automatically up to date. When you check the client address table there is no expiration listed.