Hi K,
Yep exactly the same symptoms as you, 4 days before I went to the USA for 3 weeks. Lehmans were initially very good over the phone but when they sent it back with a completely different problem that they had caused and I rang them back complaining they had caused a further fault, there attitude changed completely, hence the "electronics" quote.
Probably asking for trouble as Ive bought a second 1D3, although Ive not gone above 3000 acts on either body. The one that went back had only 1500 on it when the problem started. Both seem to be working fine, but I always have in the back of my mind "when will it happen again"
Completely off topic picking up a Canon 300mm f2.8 IS tomorrow from Calumet in Liverpool can't wait.