This thread reminds me of a call I fielded during my stint at IBM. IBM sold a beautiful Netvista X41, a rather expensive all-in-one PC which incorporated the hard drive and system board stacked behind the LCD display. The disk drive and CD-ROM drive dropped down from inside the stand that supported the monitor. This created the illusion that the computer was simply a keyboard and monitor, and looked very clean. Especially when bundled with a wireless keyboard and mouse. It was no secret to those of us in the know that the RF shielding of this computer was minimal at best, though I can't go into detail as to the problems that caused. Suffice it to say, such a design makes the task of adequate RF shielding nearly impossible, and IBM did an admirable job. You just can't have your cake and eat it too.
On to the call. A customer had one of these beauties that would act up. They had another IBM computer in a steel tower case which did not act up at all. We had sent out replacements, and they failed as well. Really odd behaviour that couldn't be reproduced, but made the computer unusable. The customer went through the effort of having the place rewired, giving the X41 its own grounded outlet, but oddly, the problems persisted. After all this, including product exchanges at IBM's expense, I discovered the cause of the problem: This customer had this computer set up in a trailer located directly under live high-voltage overhead power lines. These did not affect the computer housed in a steel case, but were causing the X41, with much less RF shielding, a wide array of odd and unusual problems.