To solve my problem I followed these instructions:
follow these steps EXACTLY
1. Create a folder called update onto your C: Drive on your harddrive
(open my computer, click Drive C)
2. Download the these 2 files and put them into the update folder created
http://gbatemp.net/index.php?download=469
(N Card 1.23o update)
http://www.dsgba.com/down/nand_stable_16.zip
(N Card beta 16)
3. Plug in the N Card writer into slot 2 and into an empty usb slot on your PC
4 Switch on your NDS holding Buttons L,R,A,B and DOWN to do a format, RESTART YOUR NDS AFTERWARDS
5. Switch on your NDS again Holding Buttons L,R,A,B and UP to put the card into flash mode. (USB SAFE BLOCK)
6 Goto the update folder were you put the downloaded files and extract the NCARD 123o update (unc_123o_english.rar) .
You should now have 2 folders UDISK and DSYSTEM,Go into the UDISK folder, with the NDS in flash mode and connected to your pc via the usb writer, click on the NAND_256k_ENG.bat file, after it has completed RESTART YOUR NDS AGAIN.
7. Switch on the NDS with buttons L,R,A,B and Down again to do another format, once it has completed windows will regonize a mass storage device, copy the DSYSTEM folder from the update folder created earlier .
once restarted your nds and card should be working as normal,
Once you have done this upgrade to the newest Mk5 Firmware and you will be okay.