It's possible that you still have a clutch issue. If you had a leaky master cylinder( I think you got taken on its replacement BTW) and you continued to operate the vehicle. It's possible that you have been changing gears without having full disengagement of the clutch, or with the clutch slipping. If this where the case it is possible that you have over heated the pressure plate. This, in turn, could have damaged the clutch release springs. This may be part of the spongy feel that you are experiencing. While you were having your original problems did you happen to smell anything?