Wireless network card frequently goes AWOL - sometimes it fails, not showing in device manager or icon tray / other times it works fine

Problem:

My Dell Latitude D600 (XP SP2)  has developed a chronic wireless networking problem in the last 4 weeks that tech support hardware and I cannot fix.

I would greatly appreciate any ideas/advice. 

Windows frequently doesn't recognize my TrueMobile 1300 WLAN MiniPCI Card when it starts, and I must shutdown and power on several times before it appears in device manager without a ! or a ?, appears in the icon tray, and then works fine.

This recognition problem will also occur with other hardware: the Broadcom Integrated Controller, the 02MicroSmartCardBusReader and others.  The Device Manager will show some "!", "?", or "unknown device" on most start ups.  I also get Found New Hardware messages and the Hardware Install Wizard appears. Then, other times it all gets recognized during a start up, and it all works fine, including the wireless adapter.

Other symptoms are: 

1) Ethernet tray icon almost never appears (but port works and both LED lights work),

2) Network connection doesn't appear in smart bar menu when network adapter doesn't "load"

3) Powering on sometimes fails. I press the power button, lights come on, but drive doesn't spin and then all power goes off. it eventually works after several attempts. and sometimes no problem powering on at all. This problem began about the same time as the wireless networking adapter problem.

4) I'd occasionally get a blue screen error when this all began, but this no longer happens.

5) Computer also wouldn't shut down completely 50-60% of the time.  I'd have to hold power button.  I'd did do virus scans and checked msconfig  for strange startup items.  Afterwards, this problem rarely occurs (but it did happen once yesterday).

6) Found a very suspicious item in the startup menu that is located in WINDOWS\SYSTEM32\spool\DRIVERS...  and had "exe.***"  (this gets blocked by forum - it's exe. and the letters F and U together), in the listing, which I now suspect  is related to the *** (again, F and U together) rootkit malware. I don't know what to do about this, as AVG virus scan and spybot don't notice it. It's still in the startup list but now unchecked.  It doesn't currently appear in task manager.  Still, I fear the malware damage may already be done in my drivers folder, and it might now be hiding itself somewhere else.

7) I get "virtual memory too low" warnings whenever I'm running a lot of stuff.  Strange thing is it appears even when I'm not adding a new task.

8) Windows task manager doesn't show anything suspicious in processes or unusual cpu usage.

9) Wireless connection used to be called "wireless connection 2" before this began.  Now it shows "wireless connection 4" since I used a network wizard.

9) Final symptom is that when wireless driver loads on startup everything can work fine.

Attempted Fixes:

Updated the wireless network adapter and broadcom integrated controller drivers successfully.  BIOS is the latest version.

Used Device Manager to reload drivers whenever it showed a "!" for hardware.  This might have helped for the next start up, but never eliminated the problem.

Ran AVG (Free) virus scan, it found a few viruses, which were removed without solving the networking issue.

Ran Spybot, which didn't find anything special when problem started. However, with the last update, it found one trojan in SYSTEM32\nvs2.inf - so removed it.

Ran full pre-boot diagnostic in BIOS, which didn't find a problem.

Tried startup with CD drive removed to see if it was affecting the powering on or impeding the recognition of other hardware - did this with a Dell tech last night. This didn't solve the problem since the wireless didn't load on the next boot.  Also updated the CD drive driver.

Experimented with ethernet cable connection to internet.  it worked even though the tray icon wasn't visible, and the broadcom device didn't appear in the device manager.  after it connected the icon appeared and  the hardware showed in the device manager??  Then, next start up it was gone again.

My Theories:

There is a trojan or virus that is interfering with my hardware drivers during the boot.  It may also explain the virtual memory issue and the powering off issue.

I have a virus that has affected the wireless network card.  I read something online about how older drivers for the Dell TrueMobile 1300 WLAN could be exploited to allow a breach in certain wireless channels. This might account for the change to connection 4 from connection 2.

I have a hardware device that is in it's death throes.  Sometimes it has difficulty booting up and in the process it interferes with the recognition of the other hardware, such as the WLAN adapter.  I suspected the CD drive, which boots before everything else, but after pulling it out without a new result, I now suspect the broadcom gigabit integrated controller may be going bad.

The motherboard is going bad, impeding the communication with the hardware devices.  Yet, when it works, it works.  The motherboard was replaced a year ago to upgrade to a higher chip and fully tested.

Need Help:

I'd like to keep this computer since it runs fine when the wireless card functions.  So, please help with any ideas or suggestions.  I can see from web searches that this type of  issue with device manager errors is common . Finding the right fix is another story.  Dell Tech Support has actually been pretty helpful with drivers and hardware testing, but they can't pin down the problem and now want me to call the overpriced paid support.  I'd rather try this board.

Thanks,   Mark