Felder signed the contract in 1994 under the "duress" of Glenn telling him "sign it by sunset or you're out of the band." However, he was unhappy and complained constantly. As Glenn put it, Felder didn't care about how much HE was making; he only cared about whether or not he was making as much as Glenn and Don H.
In the late 90s, Glenn and Don H wanted to redo the contracts again. This time, Felder balked at signing; he'd gotten his lawyer involved. Instead of giving Felder another ultimatum, they just fired him. AFTER Felder was fired, he said he'd sign the revised contracts if they would just let him be in the band again, but by then it was too late.