If I understand you correctly, you turned off the computer while the flash drive was still plugged into it. Then you removed the flash drive and plugged it into a different computer -- and the flash drive threw up those weird boxes with "still in use" and "do you want to force a dismount."
I haven't seen that on my flash drives, but I always delete any pre-installed software that comes with the flash drive -- and usually format the flash drive too -- before using it.
My guess is that it's this pre-installed software that is causing this behavior. Maybe your other flash drive doesn't have pre-installed software -- or uses a different type that doesn't kick up a fuss when you remove it from a computer that's been turned off.
This is the sort of question Inland would be better able to answer.