No it doesn't. At least not now and if it does it's a bug.
That was the case when they first introduced the blue slot system and I think some people still say that because they haven't really understood that the bug is fixed.
Just for the record, if you DO have two of the same item equipped then, yes, the chance is doubled (so having 4 daggers for example would give you 4x the chance of breaking as having just one)