Sounds like you're getting closer all the time, but for the S2 sigs you'll need to have the dish peaked perfectly to get all that you can. S2 are harder to pull in and they say a BIGGER dish is always beneficial, at least in C-band anyway.
I too have trouble getting some S2 sigs, I have 5 Ku dishes and 2 C-band dishes and I'm still working out all the kinks to get the best sigs possible. Just like a drag car, always tweaking to get every drop of performance.
Tell us about your dish setup so we can help you better. type, size, etc., and location is a factor sometimes too.