the issue unfortunately has not been addressed by Apple. i've read that it is a issue that they are aware of, but no fix yet. lucky for me my company paid for the computer, but i have to deal with the short comings of it.
i too have owned and used macs extensively in the past for graphic work, but this is the lowest of low for a high end machine. i've heard the the new iMacs are also plagued with problems. You have to wonder if quality & hardware testing is starting to lack since apple has become more main stream?