There's something strange going on here...

If I were you, I'd use my free yearly pull on all three credit reports right now and thoroughly check every detail. I'd also invest in the free 10-day trial at myfico.com to get a real FICO score and use their simulation tools to figure out what's hurting you.

If nothing turns up that way, I'd look at these numbers to make sure they match "good" parameters:

Average Age of Accounts > 5 years
Utilization, which is balance reported compared to credit limit (on each card and overall) < 10%
# inquiries in past year < 6 (on each report)

If you're still stumped, feel free to post that info here and maybe we can troubleshoot. Otherwise, the best advice is probably to have no inquiries for a year and start fresh.