Band in CNT

I recently ran a cycle course PCR reaction on 09/15 using the fancy thermocycler on the first bench. a strange band appeared at about 100bp in my NTC lane when i ran the gel of my amplified samples. The picture is a bit blurry:the lanes on the top left are for wash 3 (cycles 9, 13, 15, and 20). the lanes on the top right are for wash 0 (cycles 9, 13, 15, and 20). the lane on the bottom far left is the NTC and the lanes on the bottom right are for elution 1 (9, 13, 15, and 20). I am well aware that not much appears to be amplified here, which is why i am running another cycle course on my wash 0 and another NTC to see if the band appears again, as its original source is not apparent from the gel.

when running the gel, i used a rig that already had the TBE in it from someone else's previous gel run (no clue who) and im pretty sure it was one of the orange rigs -- although i doubt that matters at all.

From the best of my powers of deductive reasoning, the only specific information on aliquots that i could say for sure is:
-4mM dNTP (2/8/10)
-diH2O (9/7/11 ABR)
-100bp ladder (9/2/11)
-6X orange dye + EtBr (10/27/09 SKP)
none of the 10xPCR buffer or primer aliquots are labeled with dates.

All in all, i won' be sure if this is an actual artifact like Gwen was talking about until i complete my wash 0 and NTC cycle course check, which should be tomorrow sometime.
-Cori Booker