ive gotten that too.. after awhile does it subside? for me it was just my boot being too tight. you said you tried that so maybe you just have a bad fitting boot.
It goes away when I rest it after a few runs and breaks then it's sweet for the rest of the day but it's not a sacrifice worth settling for, as the pain becomes unbearable and annoying stopping all the time in that periodive gotten that too.. after awhile does it subside? for me it was just my boot being too tight. you said you tried that so maybe you just have a bad fitting boot.