Bells'll be ringing

A couple weeks ago i graduated to the 110lb dumbells on the flat bench press but after the 2nd set of 5-6 reps, they felt so good, i did a third set of 5 reps with the 115s. Well, something strange happened then. The next week i could barely get the 110s up. This monday was the next week after the weak week , and i i backed off to 90s just to do high-reps and get solid on those again. I'm thinking maybe it was an issue of not carbing up adequately the night before. This monday i'm going to shoot for the 110s again and see how it goes. We'll see....