Hotel Don Paco is quite nice — friendly staff, comfortable rooms, pool on the roof, etc. — but my visit happened to coincide with two unpleasant events: a breakdown in the internet service, and the arrival of several hundred children on some sort of tour (I'm not sure of the exact number, but judging by the noise level...).
This morning I booked another hotel, much cheaper, right in the centre of the old town, in a lane off the main streets so it should be quiet. The receptionist is a very helpful young Belgian woman who interrupted her lunch break to check me in and show me my room. It's air-conditioned of course, smallish but adequate, spotless with crisp white sheets. But... the bathroom is shared with two other rooms! That's a detail I missed while hastily making the reservation.
On the up-side, the difference in price for the remaining three nights in Seville will cover half what I paid for a new camera yesterday.