Last modified: Wednesday, April 2, 2008 5:16 PM EDT Gasoline prices inch back up BY STEPHEN PETERSON / SUN CHRONICLE STAFF Gasoline prices are on the rise again after a week's reprieve following five weeks of cost hikes. Costs in Massachusetts rose 2 cents from last week, coming in at an average of $3.14 per gallon of regular, self-serve gasoline, the latest statewide survey by AAA of Southern New England Monday found. The rise is being attributed to problems with refineries and trouble in the oil producing countries. Oil prices have soared above $110 a barrel for the first time in recent weeks. After five weeks of increases, prices fell 1 cent last week from the previous week. Costs are 20 cents higher than seven weeks ago, and are within 7 cents of the all-time high. In Rhode Island, prices for a gallon of regular unleaded rose a penny from last week, to $3.19. Diesel prices, which rose 4 cents last week from the prior week, were down a penny this week from last, AAA said. Strong global demand has driven diesel fuel past the $4 a gallon mark, with those costs rising 62 cents the past seven weeks. As it is the principal fuel of truckers transporting food and most other consumer items, the price of diesel contributes to shooting up the cost of those goods. The average gasoline price in Massachusetts is 14 cents below the nation's $3.28 average. Gasoline costs hit a high in Massachusetts in 2007 of $3.04 on Memorial Day; the low for last year was $2.15 in early February. A year ago, the average price was $2.63. The range in prices for regular gasoline is 28 cents, from $3.01 to $3.29. The average prices for self-serve midgrade and premium are $3.24 and $3.35.