The bridges will usually hang after changing configuration options in the web interface. The bridge reboots, and then when the power light comes back on, it just blinks steadily. Sometimes I can still ping the bridge, without being able to access the web interface to configure it, and sometimes even that doesn't work. A couple of the bridges died while doing firmware updates. I followed the instructions on the Linksys web page to the letter, and just as soon as it starts to upload the firmware, the bridge reboots, and we end up with the power light flashing again. This happened with a couple different computers and a couple different cables.
If you're running Windows XP, try disabling Zero Wireless Configuration (its a service, disable through control panel).
That causes a lot of problems.
If Windows XP is creating a bridge for your network connections, delete it. It's not what you want or need.
The problem is the hardware, not the software. The WET54G does not have anything to do with Windows XP or any of its configuration (or auto-configuration) options. A WET54G connection to the computer is not a wireless connection, but a wired connection, unless you are using AD-HOC mode, so Windows XP zero configuration has nothing to do with it.