Whenever you receive new scores that are spaced in time, you automatically have scoring factors other than the single credit card that also effect scoring.
Other accounts age, updates can be made on accounts or collections that effect their scoring, etc.
A typical example is the simple updated reporting of an unpaid collection or charge-off, which results in FICO score impact due to updated period of non-paymnet.
Are you sure that no other accounts, collections, or public records have updated info that would separately effect a score decrease?
