At least, that's what I've heard...
Anyway, dentical twins in the family have no bearing on whether you are more likely to have twins or not. That's pure chance. However, fraternal twins in the immediate matilineal line (ie...your mom) or other matrilineal ancestors does have a bearing. Seems obvious...if you're predisposed to release two or more eggs at a time, well, obviously, you're more likely to have twins.
The "skips a generation" part comes because if your PATERNAL side has twins (grandma had frat. twins)obviously, your dad doesn't ovulate, but he CAN pass that tendency down to his daughters. So, it may very well have a "skipping" effect.
My husband has fraternal twins on BOTH sides of his family (both grandmas had fraternal twins, and there are more in more distant branches). My daughter was the survivor of an early twin miscarriage (which is the first in my side of the family as far as we know) God help our daughter.