Card reader not working if its empty when PC boots.

This is my first post here so please bear with me...

I have just built my new PC using an Asus M4A78 and had surprisingly few problems.

However, today I found that I have a problem with "card readers".

I a card reader in my printer, an internal 5 slot one (which connects directly to a USB header on the Motherboard), and I also have several external ones.

What I have found is this.

1. If I connect the Card Reader to the PC when its up and running and it works (it doesn't matter if there is a card in the slot or not).. I get the 'bing bong' noise.. The reader mounts (I see the drive letter) and then when I insert a card, Windows 'mounts' it....

2. If Reboot the PC whilst a reader is connected (and empty), when it boots I see the drive letters, but when I insert a card I get an egg timer in Windows and double clicking on the card letter shows "Please Insert disk into drive X:"

3. If Boot the PC whilst a reader is connected AND there is a media card (SD, CF, etc) in the slot and it works normally.. The PC boots, the card is readable and significantly, if I can remove the card and reinsert it (or insert another card) and it mounts.

So the bottom line is that I can only get a card reader to work if:

1. I connect it AFTER the PC was booted
2. I boot the PC with the reader connefted AND I have a card in the slot

If I boot with it empty, then I see the drive letters but it does not work and the only way to make it work is via the 2 options above...

My old PC wasn't like this and I was running the same version of Windows (XP SP3) and was fully up to date... It wasn't like this on my old Motherboard, so this is clearly something new....

I have installed all of the latest drivers for this motherboard and have upgraded to the current BIOS and its the same.. So i am now out of ideas..

This is such an obvious problem which is easy to reproduce so I don't think i am alone.. But a search of Google finds nothing, so I am more than a little nervous about this.

My fingers are crossed that someone can help..

Does anyone have any ideas?

Jon