Can't delete from SDHC card

I have been reading loads on the internet about this but I can't seem to find the solution for me.

I have 3 new 4GB Sandisk SDHC cards and an Integral USB card reader for SDHC cards.

I can't delete, rename, reformat or cut anything on the cards when I look at them on my iBook G4, OSX Tiger or my work PC running windows 7. They are read only or write protected.

I have tried...

Every conceivable position for the lock switch in the side of the card

I have tried all sorts of and numerous layers of adhesive tape over the notch on either or both edges of the card

I have tried reformatting the card on the camera

Disc utility won't let me erase

Get info won't give me an option to change permissions

You can remove pics from the card on the camera and if you plug the camera directly into the computer via the usb. This is not a long term option as the camera is in constant, I leave a card downloading while I continue to use the camera.

From what I can gather it seems to be the card reader.

Can anybody recommend one that will not transfer everything as write protected?

Any help at all?

Many thanks in anticipation.