Dissapointed with/at

[Ksenia]

Hello!
Is it correct to use 'dissapointed with/at' in gerund structures?
Or which one is correct?
And if you can, please, write me the information about Gerund if it is here (on this site).
Thanks.

[Mehrgan]

Hello!
Is it correct to use 'dissapointed with/at' in gerund structures?
Or which one is correct?
And if you can, please, write me the information about Gerund if it is here (on this site).
Thanks.

***not a teacher***

I'm disappointed about him not coming!
They're disappointed at the result.
I was slightly disappointed by her attitude.
They're disappointed in their son!
We're disappointed with the new car!

Just a few examples. Hope someone will give us some general rules.