For those who doubt my memory - I wasn't on the night flight - the record shows that there were at least three - possibly four pure jet, passenger flights affected by the Indonesian volcano - two southbound at least one northbound and at least one internal. I think one of the southbound was night and the other may have been daylight or night but ours was daylight. There have been over ninety (90) flights worldwide recorded as adversely affected by ingesting volcanic ash (I don't think that includes old Soviet Union flights).