I brought a bottle of my first brew to my LHBS for a taste test. He thought it was good but like me, felt there was an off flavor there. It's not bad, just a little something. For some reason it doesn't leave an aftertaste though, which is good. We went over my process step by step and he came up with a couple of possible causes.
One was the use of an aluminum brew kettle. Another was the use of dishwashing liquid/soap to clean equipment, fermenter, bottling bucket etc.
He didn't say that this would cause an off flavor but he did say I shouldn't have poured hot priming solution into my bucket as this will kill yeast.
Other than that the beer isn't bad. I purchased a 5 gal glass carboy while I was there for my next batch so I can rack it into a secondary.
Here are two photos:
Brew against light