Boss Jim Magilton slammed his defence for conceding three "joke" goals as the Blues surrendered a two-goal half-time lead to lose 3-2 at home to Preston North End.
The Town manager said: "We were more than a match for them for 45 minutes when we were excellent. We showed guts and character and really didn't want the first half to end.
"At the interval I told the players that the next goal would be all-important and if we could score a third it would be game over.
"We passed the ball well in the first half but stopped doing it after the interval. The goals we conceded were jokes and giving away free headers is a disease that has crept into our game. It has got to stop.
"We did enough in the first half to deserve a handsome lead but you cannot switch off at any level and we did that."
Magilton's former Oxford United team-mate and current Preston boss Paul Simpson felt his side looked jaded before the break: "We had a shocking first half but made a great comeback. It sounds a bit pathetic to say it, but we looked leggy and tired.
"Our second half display was more like we have come to expect from our players. People might think that David Nugent's goal was lucky but he gambled on a mistake and then produced a wonderful finish.
"At the interval I said that if we could get a goal back quickly we could still win the match. When we scored it gave us a massive lift and you could see Ipswich starting to wilt.
"We have made a great start to the season but have achieved nothing yet. We must keep going for the rest of the campaign but there is a real togetherness at the club which is pleasing."