why won't ethernet stay connected for more than a few hours?

Hi SurferTim, I'm really grateful for your response. Your code has been running all afternoon with only one failure and I'm putting that one down to the power cut! (New Zealand is a 3rd world country by utility standards.) This is the longest I think I've seen any Google Docs code run and I'm super-impressed with its functionality. If it stays running for the next few days I totally owe you 50 beers!

Cheers,
Le Scare