I have a Dell u2410 that has a Displayport on it. Since I have had a Macbook pro (unibody Late 2008), the monitor has worked fine with this cable. The cable also worked fine with a 2010 uMBP that I bought earlier this month, but returned to get a new 2011 uMBP. When I hooked the cable up to my new machine, it was showing all weird: like a grainy photograph. I hooked up an Apple mini Displayport-to-DVI adaptor that I have and used a DVI cable and it works fine with that.
I am guessing it's some weirdness with the new Thunderbolt port. It doesn't like the connector on the cable somehow. I'm not sure what to replace the cable with. Apple doesn't sell a mini DP to DP cable. I could perhaps buy their miniDP to miniDP cable and get a miniDP to DP adaptor.
The cable I have came from some mfg. from Amazon. I'm not sure who else I could buy the cable from.
I am guessing it's some weirdness with the new Thunderbolt port. It doesn't like the connector on the cable somehow. I'm not sure what to replace the cable with. Apple doesn't sell a mini DP to DP cable. I could perhaps buy their miniDP to miniDP cable and get a miniDP to DP adaptor.
The cable I have came from some mfg. from Amazon. I'm not sure who else I could buy the cable from.