bridge setup

I installed new strings on my Ibanez SR500 but i went from a 45-65-80-100 set to a 40-60-70-95 set, so my bass needs to be setup, especially since my frets are buzzing, more specifically on the D and G string. I press down the 19th fret and measure the space between the 7th fret and the E string...

While I'm extremely happy with my bass, one disadvantage of having a powder-coat finish on an aluminum bass is that it's very slippery. While practicing today I noticed that my bridge (Deuce D1) had worked it's way up the bass's table about 1/4" (6.35mm). I hadn't been keeping track of it so...