The U's have been superb on their travels, but they just can't get it right on home turf and they wasted chances galore as they tried to notch their first home win in three months.
Oldham threatened rarely but defended impressively, with Will Haining keeping close tabs on Colchester's star striker Craig Fagan.
Fagan hardly had a sniff of a chance all afternoon but his team-mates certainly had their share of opportunities, with Neil Danns close to breaking the deadlock after 33 minutes. Danns ran half the length of the pitch but sliced his shot wide.
Three minutes later there was almost a first senior goal for centre-half Pat Baldwin. A low throw from Greg Halford found its way through to Baldwin but his shot lacked the bend necessary to sneak in at the far post.
Oldham actually had the ball in the back of the net in the first half when Scott Vernon muscled the ball home following a free-kick by Alex Bruce, but referee Paul Danson had already blown his whistle for a foul on teenage keeper Dean Gerken.
Oldham's tenacity was summed up by their number of bookings. They had five of them, three in the space of three minutes midway through the second half as they attempted to keep Colchester at bay.
Halford had the best chances in the second period and one of his long range free-kicks dipped just over the bar and onto the top of the net in the 69th minute.
A minute later Halford really should have scored the winner. Substitute Gareth Williams had an angle shot blocked and although the rebound fell kindly for Halford, the big man blasted his shot over the bar.
Colchester have now managed just two points at Layer Road in their last six home league games.
It is their away form that is keeping them clear of the relegation zone because they've only lost one of their last eight on the road.