I replaced a working SanDisk

Question

I replaced a working SanDisk Compact Flash Reader (in use for several years) with an Ecotrends 50-in-1 reader from Office Max. It, didn't work, i.e. was not recognized by Windows XP Pro SP3. I took it back to thr stor and got a replacement. Windows now recognizes its existance but when I insert a card it says it cannot get the images from the card. I am using a powered hub for several devices. I have tried with the powe cord unplugged but this makes no difference. The SanDisk reader still works. Any suggestions?