I posted previously on 02/12/05 to this newsgroup about a flickering computer monitor which I'm sure some of you will remember. It took three additional months to sort out the problem, but it's been finally been fixed. Just posting to list the diagnosis and eventual problem for anybody else who may suffer this problem in the future.
I purchased an EMF meter which measures on the magnetic scale, and discovered that the readings throughout the house were nearly always above10mG (1uT). Frequently they rose above 30mG (3uT) and consistently in the 15mG-25mG (1.5uT-2.5uT) and the flickering corresponded to the strength of the field at any given time. The electric board didn't believe us at first that this was the problem, but eventually one of their experts agreed with our diagnosis. They told us to take readings for a week, and surprisingly, 24 hours after returning the readings to them, they announced that they'd fixed the problem and thanked us for our patience. Turns out there were some bad connections that they replaced somewhere. The readings are now down to around 10% of the readings I gave previously.
I can't say I'm glad about the six month exposure to those levels of EMF radiation (September-March), or the eye strain caused by the flickering monitor for this period of time, but the problem appears to of been resolved.
Thanks to those who helped out, even those who believed my eyesight was to blame :)