That was my first take...
Until mention of track lighting.
Now, having re-read the OP for a third time:
Question: Is this a three-phase circuit?
Did you have the amp reading taken simultaneously?
( Current flow can easily change by 0.15 A over time, as the load heats up and resistance rises. )
Is your amp-meter as sophisticated as a T5-600/T5-1000 by Fluke?
In which case, exactly where and how a conductor is clamped can shift the apparent amperage drawn by such a trivial amount.
What kind of absolute amperage reading were you pulling?
Last edited by Tesla; 12/22/12 11:22 PM.