Roy Keane saw his side hit the woodwork three times in a goalless first half but when James made a mess of collecting a high ball, Tamas Priskin put the hosts ahead.
Jason Scotland scored the second on his full debut for the club to leave Keith Millen's side second bottom with just two points from four games.
Jon Stead joined the Robins from Ipswich on Monday and made an instant return after being named in the starting line-up in a new-look strike partnership with Brett Pitman.
Pitman turned down a move to Premier League side Blackpool last weekend to sign for City but endured a quiet debut for his new club.
Town started strongly, with centre-half Gareth McAuley testing former England goalkeeper James with a header from a free-kick before midfielder Grant Leadbitter came close to an opener when he crashed a long-range drive against the crossbar.
Keane's side were looking dangerous and Scotland should have marked his home debut with a goal in the 20th minute.
Neat play released Carlos Edwards down the right flank and when he found Scotland with a low cross the former Wigan man could only steer an effort wide of the goal.
Albert Adomah then had the visitors' first effort with a low skidding shot from 25 yards which was easily held by Marton Fulop before McAuley headed another set-piece wide.
The hosts were dominating play and were desperately unlucky not to go ahead moments later when Priskin clipped the ball past James but against the frame of the goal.
Scotland flashed a header wide at the end of an entertaining first period but there was no break of the deadlock.
Marvin Elliott crashed a strike over at the start of the second half as Millen's men looked to find a way into the game before Town were incredibly denied by the bar yet again.
Scotland was the man to miss out on this occasion, sowing great strength to shrug off a challenge and thump in a shot from 18 yards which struck the crossbar and was cleared.
The breakthrough appeared inevitable and finally arrived in the 59th minute.
Town launched a long ball into the area and James came out to claim the ball but could only drop it at the feet of Priskin, who was left with the simple task of rolling into an open net.
Pitman had his first effort for City when he forced wide from the edge of the area before Scotland grabbed a deserved second for Ipswich in the 74th minute.
Priskin let fly from 20 yards and though James made a sharp save to parry the ball away, Scotland reacted first to fire in the loose ball.