I have noticed that my laptop disconnects from router once or twice a week and then waits before connecting again. It is like i have been disconnected from router manually. Router works as usual however. Why is that so? Maybe lease is expiring or something?
Additional Details:
Latitude E6420, Windows 7 Enterprise, 3Com OfficeConnect Wireless 11g Cable/DSL Router (latest firmware), DHCP server.


Please Note: I get the following message in EventViewer everytime this happens:
"The IP address lease 192.168.1.110 for the Network Card with network address 0xEC55F95E05CA has been denied by the DHCP server 0.0.0.0 (The DHCP Server sent a DHCPNACK message)."