This problem arises in 2 cases:

1. If you open a file and immediately begin scrolling (<1s), when the code is parsed, the scrolling will start back where the cursor is located.
2. If you make a change and immediately scroll the cursor out of view, when the code is parsed, it will again jump back to where the cursor is located.

Both of these happen when using the scroll wheel on the mouse. I don't believe they happen when using the scroll bars.

Has anyone else seen something similar?

nope.
What version do you use?

5.2 build 5236 and it's been around for a while.
Would it have anything to do with the code completion or tooltip delays? I have them both set half way between 0.1s and the first tic.

no, I can't replicate the problem you described in 5236.
Please try on another machine with all the default settings. If it works fine, please compare what setting makes it scrolling.

I can see it happening, but it's very quick when I only have one project in my workspace. It seems to happen, although still quite quick, once you have a 8+ files open and 10+ projects in your workspace. It seems to happen more often after using PhpED for a while and when working on a larger file (3000+ lines).

Sorry I can't produce exact steps to recreate the problem, but it's really annoying.