SD card reader problem

Hoping for some help with this one... I have a mid-2009 13" MBP (2.26, 4 gigs, 1TB HDD, SL 10.6.4) and the SD card reader is not recognizing any of my SD cards (won't mount and also not seen in Disk Utility). The cards are recognized when using a USB adaptor, and also work fine in my wife's MBP SD card reader, so I know it's not the cards. System Profiler recognizes the internal card reader on my system:

Copied from Apple System Profiler:

USB High-Speed Bus:

Host Controller Location: Built-in USB
Host Controller Driver: AppleUSBEHCI
PCI Device ID: 0x0aa9
PCI Revision ID: 0x00b1
PCI Vendor ID: 0x10de
Bus Number: 0x26

Internal Memory Card Reader:

Product ID: 0x8403
Vendor ID: 0x05ac (Apple Inc.)
Version: 98.33
Serial Number: 000000009833
Speed: Up to 480 Mb/sec
Manufacturer: Apple
Location ID: 0x26500000
Current Available (mA): 500
Current Required (mA): 500

Also, the card reader is recognized in Windows, but still doesn't detect the card when inserted.

This one has me stumped, so any help is very much appreciated.