* Dollar dips from eight-month high ahead of ECB, payrolls * Short positions in COMEX gold at record high * Gold posts biggest monthly drop in 2-1/2 years in Nov (Updates throughout, changes dateline, pvs SINGAPORE) By Jan Harvey LONDON, Dec 1 (Reuters) - Gold rose for a second day on Tuesday, rebounding from last week's 5-1/2 year low, as a retreat in the dollar prompted investors to cover short positions ahead of a European Central Bank meeting and U.S. payrolls data this week. The dollar slid from an 8-1/2-month high as the euro bounced back, with traders judging that a significant amount of further monetary easing had already been priced into the single currency ahead of Thursday's ECB meeting.
