String intonation thing

[lowlandtrees]

I have a Kania small bodied contra bass strung with Silver Slaps. Been playing nearly 3 years so relatively new to it. I played guitar and sax and took up DB in my late 50s. I have noticed that the position of the note D on the A string is not directly in line with the G on the D string. There is a half centimetre difference in the distance that you fret the notes. The two lower strings (E and A) seem to match and the two higher (D and G) match in fingering positions. Another problem with the instrument is that the angle that the strings take from the bridge to the tail piece is very sharp. This means that when you tune, the strings tend to stretch then jump as opposed to slide. I have tried rubbing in graphite.
Now it could be my duff left hand technique but I was wondering if it is possible that the instrument needs set up. I bought it from a forum member but am ignorant of the history of the instrument. I am concerned that my luthier will recommend cutting a new bridge. Don t really want that expense....can the existing bridge be adapted?
I do like the instrument. Sounds good through my EA doubler/wizzy M line and is very transport friendly

[mtroun]

Take it a to a luthier, it's got to be worth spending a bit if you like the sound of the instrument. If the action of your instrument isn't too low then they may be able to cut your existing bridge to a decent shape with a slightly lower action. It's worth getting a really good luthier to sort out your bridge though... my bass has had 3, should have gone to the last guy in the first place!