Hi, darkale, welcome to the forums!
I think that the single score that you were getting from Equifax was in fact a FICO score. Check the report to see if it says FICO on it somewhere. If this is called Scorewatch, it's your EQ FICO.
You are correct that each CRA has its own FICO scoring formula, and you will most likely have different scores from each, due to the differing formulas plus probably differing info on each report.
TU and EX have created their own scoring formulas as well. No one really knows why, because it's like having a score for a game that no one has ever seen or knows the rules of; cynics might suggest that it's to make money off of unknowing consumers. All three CRA's have also gone in together on something called a Vantage score, which combines info from all three reports (thus only one score), and concentrates heavily on the last two years. This last one is a legitimate attempt to compete with FICO scores for a share of the lending market, although it's hard to tell if they're getting anywhere at all.
Anyway, all these non-FICO scores are derisively termed FAKO's, for obvious resons. There is only one monitoring service from TU that follows TU FICO's, and it only monitors quarterly, not monthly, so you might have actually bought TrueCredit or one of its friends. TC is great for tracking changes on your credit REPORTS (as are other services that allow daily updates of all three credit reports), but you have to learn to ignore the FAKO scores and the FAKO advice. To repeat the analogy from above, the scores are from a game that no one knows or understands, and the advice is coaching for this mystery game. So the scores frequently do not parallel FICO's, even in general upward or downward movement, and following the FAKO advice can frequently hurt your FICO's.
Since you already seem to have EQ Scorewatch (which can also be purchased here), all you need to find out for a complete picture are your TU FICO and EX FICO. You can buy these individually here on this site, or what might work better over the long run is to buy the Suze Orman FICO kit (also available here.) When you buy the scores individually, they only display for 30 days and then they vanish. With Suze, they display for a year, which is handy when you want to go back and compare, or if you don't need to update often. Also, you don't have to pull all the reports at once, and if you like, you can pull EX three times, or EX twice and TU once, or similar combos. That way you won't be duplicating the EQ scores. Even Suze's advice is sometimes a bit shaky, so you might want to post it here and get some counter opinions.
Whatever you do, be sure to first Google fico discount code coupon to get at least 15% off. Out of courtesy to our FICO hosts, we don't print them here, unless it's a code that myFICO itself offers.
If you did in fact buy the TU quarterly monitoring service, and you are looking at a TU FICO score, then most likely there is something bad on his TU report that's not on his EQ report. Hit "printer-friendly" or the equivalent option to expand the accounts information, print out both reports, and compare them side-by-side. I'd say that you'll find the cause of the score difference there.
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007