We bid a job where we were over $80,000 lower than the next bidder on a pretty straight forward $975,000 communications project, using a 5% certified check as our bid security. As soon as the results were public we went a little nuts trying to figure out why we were so low. Two errors came to light, but both of them were errors in our favor totaling approximately $8,000, making it even more troubling. But we went forward with the project assuming that the other two bidders were flush with work and bid high. We found the error later. We had a very sophisticated Excel program that we developed over 10 years that worked very well and allowed our PM?s and others to easily prepare a bid and change the outcome to match the required bidding criteria. In this bid we inputted the use tax amount percentage and it flowed to the total material cost as was required by the state, and showed up elsewhere correctly for our own review. Unfortunately, at one point prior to the bid, one of our employees gained access to the password and proceeded to change the program to suit his specific needs by adding a few more macros. In doing so he corrupted part of it, creating an error that could not be found by simply reviewing totals. The tax appeared to be totaling in the material at the required 0.075, but was actually being computed at 0.0075. That was the primary reason for our low bid in addition to ? thank heavens -- the other contractors being a little bit busy at the time.