What do you mean by "an unusual time to shift"? Does it slip when shifting? Does the actual shift take a longer time? Or does it tend to shift only at higher RPMs than it used to? The first two would indicate some sort of internal problem - could be as easy as low or dirty fluid. Check the dipstick. Should be at the proper level, should be pink fluid. Shifting at higher RPMs is likely to be the kickdown cable sticking. It could also be something along the lines of a power loss problem leading you to press down on the accelerator pedal more than usual.

- alex