Using a Transend 16GB sdhc, onboard card reader.

This is what I get when I insert the card
$ dmesg | tail
usb 4-1: device descriptor read/64, error -71
usb 4-1: device descriptor read/64, error -71
usb 4-1: new full speed USB device using uhci_hcd and address 11
usb 4-1: device descriptor read/64, error -71
usb 4-1: device descriptor read/64, error -71
usb 4-1: new full speed USB device using uhci_hcd and address 12
usb 4-1: device not accepting address 12, error -71
usb 4-1: new full speed USB device using uhci_hcd and address 13
usb 4-1: device not accepting address 13, error -71
hub 4-0:1.0: unable to enumerate USB device on port 1

lspci
00:00.0 Host bridge: Intel Corporation 82915G/P/GV/GL/PL/910GL Memory Controller Hub (rev 04)
00:02.0 VGA compatible controller: Intel Corporation 82915G/GV/910GL Integrated Graphics Controller (rev 04)
00:1b.0 Audio device: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) High Definition Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) PCI Express Port 1 (rev 04)
00:1c.1 PCI bridge: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) PCI Express Port 2 (rev 04)
00:1d.0 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #1 (rev 04)
00:1d.1 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #2 (rev 04)
00:1d.2 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #3 (rev 04)
00:1d.3 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #4 (rev 04)
00:1d.7 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB2 EHCI Controller (rev 04)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev d4)
00:1f.0 ISA bridge: Intel Corporation 82801FB/FR (ICH6/ICH6R) LPC Interface Bridge (rev 04)
00:1f.1 IDE interface: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) IDE Controller (rev 04)
00:1f.2 IDE interface: Intel Corporation 82801FR/FRW (ICH6R/ICH6RW) SATA Controller (rev 04)
00:1f.3 SMBus: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) SMBus Controller (rev 04)
03:02.0 Communication controller: Conexant Systems, Inc. HSF 56k Data/Fax Modem
03:08.0 Ethernet controller: Intel Corporation 82562ET/EZ/GT/GZ - PRO/100 VE (LOM) Ethernet Controller (rev 04)

$ lsusb
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 002: ID 15ca:00c3 Textech International Ltd. Mini Optical Mouse
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 002: ID 413c:2005 Dell Computer Corp. RT7D50 Keyboard
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

Running sidux with 2.6.28-5.slh.3-sidux-686 kernel.

There is a difference between a SD card reader and a SDHC card reader. SDHC card readers are backward compatible to the older SD standard. Since the SDHC standard is newer than many SD card readers they cannot read the SDHC cards.