Using OSX Yosemite 10.10.1 I routinely see the cursor move unexpectedly regardless of filetype and this happens in both build 3065 and 3066. The movements occur seeming as a result of Sublime having lost focus and then regaining focus. An Example that occurs alot is as follows:

1function foo(a) {
2 var x = a;
3 | <- note current cursor position is 4 spaces from margin beneath where the function call begins
4}

At this point assume I quickly switch (whether via mouse or keyboard) to view a website or some other program on my screen for 1 second or 100 invariably I will find the cursor has moved to be incorrectly aligned at the margin:

1function foo(a) {
2 var x = a;
3| <- the new position is now at the margin, aligned with the function call above
4}

Another movement that occurs is the cursor will drop down to a line beneath the one I am currently working on if that line below is blank (although that line seems to also need to be “in existence” as I have not seen this able to create a /n to do this).

I don’t think there is anything particularly radical about my set-up and I used Sublime in the past without this issue.