Small problem with Lexar UDMA reader

[David Sutton]

I've just bought a Lexar UDMA card reader. When I put in a cf card and plug it into the usb port on the front of the computer, it takes a long time to come up in “My Computer” and shows no images on the card. In fact doesn't show a card being there at all. If I plug it into a rear usb port, the card comes up straight away and the files show up.
So I tried it out on my laptop and the same thing occurs. Some usb ports will show the card and its contents straight away, and others take a long time to register the reader and then show nothing present.
My other card reader (Kingston) doesn't have this problem.
Is this a voltage thing? Any suggestions?
I guess my main concern is its reliability when I'm travelling.
Windows XP. SanDisk ExtremeIII.
Thanks, David

[Panopeeper]

It must be a power supply issue (that's what you wrote "voltage"). I have such problem with external hard drive without its own power supply; it occured with an external CD/DVD drive as well.

[David Sutton]

Thanks for the fast reply Gabor. I remember reading somewhere that not all usb ports in a computer are created equal as far as the power supply goes. I suppose if I stick to the ones I know will work, then I can keep using this card reader and not worry.

[fike]

I've had similar problems with USB ports that are on a PCI expansion card.  Ports that are directly on the are always best.

Routing of the wires insode the case could easily be causing EMF interference.  Those wires that run inside the case are not shielded in any way and they may be hanging across a fan or high voltage line.