Using TWO external monitors with a Latitude 410

I've managed to quite easily setup Dual Dell 19" LCDs with Latitude D410's connected to the D-Dock Docking station. Now for some reason the laptops run slower when connected in this setup. For instance, launching IE takes about 18 seconds from the time I click on the link for it to start up. This also happens with the 4 other notebooks setup in this configuration and is not just limited to IE.

 

If I remove the laptop from the docking stations they work flawlessly.

 

Details:

 

Dell Latitude D410, Pentium M 2.13Ghz, 1GB RAM, 60GBHD, Dell 1370 Wireless.

All Latitudes use the wireless card to connect to the network.

 

I've called Dell technical support and was quite surprised when I was told that this configuration would not work with Dual Monitors. I had explained in detail to the Sales rep what I needed to do. Unfortunately he also sold me 5 ATI PCI gfx cards to install into the docking station to allow this setup but the card only prevented the laptops from booting. After removing the ATI cards I was able to connect the dual monitors to the VGA and DVI connections on the docking station which has led me to the current problem. Why the slowness????

 

Can anyone suggest anything for this ?