Same, its always during this time.I used to get the 502 bad gateway message between 09:10 and 09:20 GMT which was when the server was backed up. I've not been here at that time of day for the last few days so I don't know if it still does it. (Those of you in different time zones will need to find out when that is where you live )
During the 12 hour forum 'outage' (which for me was 17:45 on 31 March to 05:53 on 1 April) the forum did load but although I could read everything I couldn't post anything.