Patch panel confessions
Horrid.
Absolutely that'll be the problem.
You need to rewire both ends so that they match either the 568a or 568b standard. Not wiring it correctly will result in the errors you describe because it relies on differential signalling for noise free transmission. Don't worry if you don't understand that. Basically a plus and a minus pair are twisted together inside the cable.
I'd start with a jack at a time.
http://en.wikipedia.org/wiki/TIA/EIA-568