I just got two eport replicator plus docking stations for my M6600 one for work and one for home. I finally got one setup and I cannot get my monitors to work on the DVI ports. I connected one via the VGA port on the docking station and it worked fine.
I only have the ATI video so would that be my problem? I didnt think using the DVI ports required the Nvidia cards but perhaps I was mistaken. I am using DVI-D single link cables and they work fine to my desktop Nvidia card. Dont have a DVI-D dual link cable around to try right now.
PowerConnect Application Notes:http://www.dell.com/content/topics/global.aspx/solutions/en/pwcnt_papers?c=us&l=en&cs=555
PowerConnect 6200 Manuals:http://support.dell.com/support/edocs/network/pc62xx/en/index.htm
I am having a similar issue. My suggestion is to try a dual link cable.