Not to add insult to injury, but first rev. products are generally a rushed prototype for any company.
My 'guess' is Jobs wanted these 'out the door' by a specific time, and they didn't get enough bench testing time, so the consumer gets that job.
What really 'shocked' me personally was the very same issue happened on two 'brand new' machines within a few weeks of each other. If it happened one time, then it's just a fluke to me, but twice on two machines is a either a bad production run, bad design, or poor/cheap components.
If it was a software issue, it would be fixed by now through an update, but my 'guess' is Apple has already dispatched an internal memo that says, "If you see 'this'....then take it back, exchange, refund, repair, etc..". In a few weeks/months, there will probably be a "Repair Extention Program" like there was for the iBook G3s and the iMac G5s.
I know Apple is not the only company who has this type of issue w/ first revisions, but when you go to their support site, there's 3+ links for Repair Extension Programs...something I've yet to see on any other mfgs site. The only other computer manufacturer I can recall to have such "issues" w/ their notebooks was Toshiba when the P4 models came out. They decided to put a P4 desktop series chip into a Satellite model, which was grossly under-cooled. My g/f at the time had this model and it went back to Toshiba 3x before they gave her a different model. A few months later, she got something in the mail about a "Class Action Suit against Toshiba" because of that specific model she had. To date, I think Toshiba is still working around that debacle by either replacing or constantly repairing the machine. However, the model she got in exchange was P3-M series that didn't have any problems. They compensated her w/ extra RAM and DVD burner.
My best friend and his wife owned an iBook G3 900Mhz model that went in 4x in 2 years time for the logic board issues. Apple finally gave them a new G4 model, but only after they said they were going to go to small claims court and try to get their money back for the machine. The G4 model they got hasn't had a problem since they got it, but they both said, "It's our last Mac". Which is sad because I really did like the iBook line.... The 900Mhz was far from a first revision of the iBooks, so Apple no doubt knew of the problem(s) that plagued the G3 line. Whether or not it was a manufacturing or engineering problem, the fact is they were being sued because of it and that's why you have an open-ended warranty on those lines (hence why they keep extending the warranty exp. date).
I would really like to see Apple do well, but it seems their shift in focus has been to leave both manufacturing and QC to the contract manufacturers. :-(