Roy Keane's men were among the favourites for promotion, but it is Alan Irvine's Preston who sit in a play-off place, unbeaten so far, while Town are in the bottom three and without a win.
The Blues missed a great chance to claim three points in this game, having had a full half against ten men after Callum Davidson was dismissed for deliberate handball on the line, which led to Jon Walters' equaliser after Ross Wallace had fired the visitors in front.
Preston could have scored in the third minute when Pim Balkestein misjudged a long punt forward which went over his head, but Richard Wright did well to block Jon Parkin's shot.
Wallace, Davidson and Walters were all booked in a feisty couple of minutes before Wallace put Preston ahead, taking a deep ball from Billy Jones, twisting Alex Bruce inside and out before firing home off the inside of the post, through the legs of both Bruce and Gareth McAuley.
McAuley did well to block a Parkin shot after Jones had put him through, before Ipswich had their first effort on target on 37 minutes when a defensive error saw a Lee Martin cross drop to Pablo Counago, but his shot on the turn was palmed over by Andy Lonergan.
Tamas Priskin had a close-range shot blocked by Richard Chaplow from the ensuing corner, Walters shot wide after a one-two with Counago and then Wallace tested Wright with a 30-yard snap-shot.
Ipswich were gifted a chance to level when Jack Colback's cross was fluffed by Lonergan and Davidson handled to deny Liam Trotter's goalbound shot, and although Lonergan dived to his right to save Walters' penalty, he rammed in the rebound.
Ipswich fans anticipated their side going on to claim all three points at that stage, but the visitors dug in well, and even had their moments on the break when they could have snatched victory.
Martin had an early effort deflected wide, and from his ensuing corner McAuley made good contact with his downward header but Lonergan made a fine sprawling save on the line and the loose ball was hooked clear.
Chaplow robbed Tommy Smith and tried to feed Wallace, only for Colback to get back to clear narrowly over his own bar, before Keane made a triple change, sending on Alan Quinn, Jon Stead and Connor Wickham for Martin, Counago and Priskin.
It worked well initially as Wickham had a 25-yarder saved by Lonergan and then Quinn crossed for the teenager to head wide, before Trotter put Wickham clear but his touch was heavy and the chance was lost.
Wickham's hooked effort dropped just wide of the post before a Preston break ended with Chaplow crossing to the far post where Wallace sent in an angled drive which Wright tipped around the post.
Ipswich kept going, but they had run out of ideas by now and only really looked dangerous on set-plays, with another McAuley header, this time from a Quinn corner, dropping onto the roof of the net.
The visitors held out quite comfortably, despite five added minutes being played at the end, and Keane's men again departed the pitch to a chorus of boos with the manager anxious to add new faces before the transfer window closes on Tuesday, and on this evidence they need them.