Sorry, my brain must have been sleeping - I meant to post the command for generating a hash, not the keystore, here's what I use:
keytool -exportcert -alias ALIAS_HERE -keystore path/to/mykey.keystore | openssl sha1 -binary | openssl base64
which is the same as what you just posted - so not sure what's going wrong. Maybe you could try doing a build command instead of run and install it manually, but it sounds like it should be working. Have you double checked you're referencing the correct Facebook App in your code as well? That might explain the different key hash.