Our dishwasher runs normally but then while sitting water will collect in the bottom - an inch or so of water in a few hours. If we turn off the water intake to the dishwasher it almost stops but we did that while we were gone for a week and there was still some water collected in the bottom when we returned. It drains just fine when we run the drain cycle.

I realize this reply is somewhat tardy (...) however I've got the identical problem on our Whirlpool dishwasher. The continued leakage of water into the dishwasher even after the house water supply to the washer is turned off is probably caused by TWO things - the inlet valve on the dishwasher needs replacing since it is leaking and the house/undersink cutoff valve to the dishwasher is typical of such valves and actually doesn't work very well (!).

In my house ALL the valves (undersink, under toilet, etc) that I've had to turn off to do whatever have leaked after turning them off - every one of them. Though the leaks are not dramatic, over time they can cause problems if you are relying on them actually being OFF - a drip here, a drip there, before you know it it's a LOT of water (especially if it is a somewhat fast drip). As an amateur with such plumbing I am aghast that this is so, surprised that this is so, and wondering if there's actually a solution to the problem - like using higher quality cutoff valves everywhere in the house?

But, in any case, the OP's dishwasher problem sounds identical to mine and others that have posted here - water leaking into dishwasher - bad inlet valve.