Dull Hull problem for Bruce.
Four games have reaped just two goals - Curtis Davies' header in the frustrating draw with Cardiff the latest.
Bruce's misfiring men had 18 shots against their fellow new boys, with Danny Graham, without a goal since leaving Swansea in January, spurning two great chances.
Bruce said: "Defensively we're very sound but we can't keep relying on the idea that we're going to keep a clean sheet.
"You sound like a broken record. How many times have I stood here and said 'We should have won by four?' "It's just such a frustration, because some of our football at times was good. But I can't keep saying the same thing. We have to take our chances."
Cardiff had created little before the break but an attacking half-time change by Malky Mackay reaped rewards as Peter Whittingham finished a wonderful passing move with a sweet left-foot finish.