Forest at least improved on their inept recent performances against Coventry City and Plymouth Argyle but they could not clinch a potentially vital three points despite taking the lead at the start of the second half.
Danny Webber missed an early chance for the Blades when Forest failed to deal with a long throw, but the striker headed over the bar under pressure from Paul Gerrard.
Webber then fired wide after being sent clean through down the left-hand channel and Gerrard then had to be alert to keep out Jon Harley's 25-yard strike.
Forest failed to trouble Paddy Kenny in the United goal and the visitors again went close to taking the lead on the half-hour when Alan Quinn's far-post cross was fired across the face of goal by Leigh Bromby.
Gerrard then kept out Quinn's effort as Forest struggled to create a clear-cut opening.
Forest surprisingly opened the scoring at the start of the second half when Kris Commons headed powerfully home from Matthieu Louis-Jean's excellent right-wing cross - it was their first real attempt on goal.
But United equalised when the unmarked Quinn scored midway through the second half after great work by Derek Geary and Andy Liddell.
The result leaves Forest five points away from safety while the Blades are seventh, one point below the play-offs.