The story of our lives as violinists ..

Here are my thoughts: slow it down .. believe it or not, our brains can recall information faster than it is possible to play.  It's just a matter of muscle memory.  But muscle memory is more than just memorizing the notes; it's also memorizing the position for the correct tone, the bow speed & positioning.

However, while performing it slower to get it right is needed, you have to "pretend" that you're playing it at full speed.  That means, most likely you wouldn't be using much bow when playing a flurry of notes.  So when practicing, it does no good to use full bows when at normal speed that wouldn't be the case.  Also, and this is KEY, while you're slowing the tempo, do not slow your shifts.  Make sure whenever you shift positions, you'd do it as quickly as if you were playing it at full speed.  There should be no audible clues that you're shifting (like sliding into the note etc).

Lastly, with complicated passages where there are multiple shifts, break them down into segments.  As you become more proficient with the segments, slowly integrate them into one complete passage.  Then slowly *and I do mean slowly* increase the tempo, to even faster than the normal tempo.

Hope this helps

Good luck!!!