Wireless network connectivity drops out ..

Hi..
I did install and configure wireless GetGear network adapter and Netgear
WAP, running WPA/PSK. It hs been running fine for several weeks. All of a
sudden the wireless network connection drops out from time to time, usually
after a perios of time when not in use. I also observed it dropping out 10
minutes after boot, when I was surfing the internet.
The Event Viewer, System Tab then indicates a row of app. 44 yellow triangle
warnings:
Event Type: Warning
Event Source: Dhcp
Event Category: None
Event ID: 1003
Date: 25-07-2006
Time: 17:05:49
User: N/A
Computer: JDBCOMPUTER
Description:
Your computer was not able to renew its address from the network (from the
DHCP Server) for the Network Card with network address 00146C82DFD1. The
following error occurred:
The operation was canceled by the user. . Your computer will continue to try
and obtain an address on its own from the network address (DHCP) server.

For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.
Data:
0000: c7 04 00 00 Ç...

this Warnings are mixed with the Informaion Events shown below:

Event Type: Information
Event Source: Tcpip
Event Category: None
Event ID: 4201
Date: 25-07-2006
Time: 17:05:49
User: N/A
Computer: JDBCOMPUTER
Description:
The system detected that network adapter
\DEVICE\TCPIP_{AAD2BD2E-3F8F-4FE1-8627-74442FDF6E6D} was connected to the
network, and has initiated normal operation over the network adapter.

For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.
Data:
0000: 00 00 00 00 02 00 50 00 ......P.
0008: 00 00 00 00 69 10 00 40 ....i..@
0010: 02 00 00 00 00 00 00 00 ........
0018: 00 00 00 00 00 00 00 00 ........
0020: 00 00 00 00 00 00 00 00 ........

After this scenario it us usually difficult to reconnect to the network.

No additional software has been installed. No configuration changes has been
made to the computer.
Could someone help, please ?

Thanks
Anders