Has anyone run into poor seed germination from seeds purchased presumably
fresh this year. I think it may be because the seeds may have been cooked
during storage.

Why would you say that they 'may have been cooked'?

In particular, I bought seeds several times from Target with the brand
name
Fordhook. They are prepared by Burpee. Out of about eight banana squash
seeds, only one sprouted. Out of their IIRC Big beef only a few
germinated.

I bought string beans(11/12 germination rate), Big Beef(15/16), and
canteloupe(18/18) from Target( Burpee's Fordhook )also, but have had great
success with them as the numbers indicate. And they're doing very well after
germination. The Big Beef were so small when I planted them that I thought I
never get any tomatos(2-inches in mid-May), but now they're all over three
feet with tons of fruit.

Am I imagining this or do you really have to watch out for the retail
environment in which seeds are stored?

My local Target has them in a rack in the gardening section of an air
conditioned store. I supposed refills could be stored in the store's boiler
room, but this particular one doesn't have that much movement of the seed
packets.

Rob