Help. Primary middle monitor is generic pnp? What do I do?

[DFischer]

I have 3x 2407WFP's.

My middle one is hooked up to displayport.

My middle one is recognized as a "generic non pnp" monitor instead of 2408WFP.

How do I fix?

I also noticed one of my monitors is identified as 2407WFP-HC vs 2407WFP (I didn't know I had one different than the other). Is that bad? They're visually the same exact thing... Can I trick it?

Using this adapter =>

http://www.amazon.com/gp/product/B004071ZXA/ref=oss_product

No matter what monitor I try it out on I get a 1600 max resolution instead of 1920... is the adapter bad?