In my GitHub settings, in the "Emails" tab, I have "Keep my email address private" checked, which means my real email address is not recorded when performing git operations.
I contributed to a project that has tip4commit enabled (peercoin.net) and signed in to tip4commit.com with the "Sign in with GitHub" link, but it grabbed my real email address instead of the fake email address used when my pull request was merged. Thus, I didn't receive the tip.
What's even stranger is that the project I contributed to also has peer4commit enabled, yet when signing into peer4commit.com, at first it did the same thing but then later grabbed my fake email address and rewarded me the PPC.
Since there's no way to change my email to the fake email I used when submitting the pull request on tip4commit.com, and since I Imagine this might affect future users, I hope this gets fixed!