Macbook Air NOT mounting ANY external drives, sd cards

[loremipsum]

I recently got a 2008 Macbook air with 10.5.6 installed. It was a floor model. also, the date when i booted it up was before 2001 for some strange reason.

anyway, i have a WD 320 gb passport, usb ind. power external. It worked just fine two days ago, but now i upgraded through "Software Update" and..

-It does not mount in finder, sidebar, or disc utility.
-the power light turns on
-cannot force mount with 3rd party software (Mount Me! 2.05)
-the MBA will also not mount any SD cards!! I have tried two different cables and even my printer!!
-iPod Touch works just fine in the same port
-SD cards and WD Passport work fine in anything else

Please Help!! I'm fairly Mac literate so give me your all!

 

[JediMeister]

Try an SMC reset, and make sure you follow the steps for models with a non-removable battery. Also, with the drive/card-reader connected, take a look in the USB Device Tree list found in System Profiler, then selecting USB under the Hardware sidebar. Does it even detect that something is connected? I don't think formatting would be an issue for the SD cards but perhaps there's something unique to the the Passport that doesn't mount on Mac's? When you say the card reader and drive work with "everything else" does that statement refer to Macs & PCs or just Windows computers?