Yes, jazzypinkpuppet it did occur to me that all the news coverage of the problems might lead to people who would have otherwise sent applications off in July, August and September, sending them off early, just in case, thus increasing the volume that the passport offices have to deal with.
I'm not sure when they calculate the three weeks from. My email said to allow three weeks if you send the application via check and send and to allow four weeks if you send in the normal post (to allow for postage time). So doesn't that imply that the three weeks is calculated from the date you submit via check and send and you don't need to allow an extra week for postage time?
All academic of course as they clearly aren't keeping to the three week service standard, however calculated, for many applications at the moment, as illustrated by the surprise from the Belfast Office today that I should expect any progress at all when they've "only" had my application since 5 June.
I do still have time in hand, having sent it off in good time, but it's hard not to worry reading the stories on this thread.