Boydie
Is anyone else having issues with VERTICAL zoom?
You know I am.

Well, below is an issue I reported to CW several days ago (but the ticket status is still "new")
Try reproducing this, because I believe it's directly related to your issue.
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1. Load the Normal project template
2. In the Track View, go to Options > Mouse Wheel Zoom Options, and set up the options like this:
http://i.imgur.com/Kh4V3EI.png3. Minimize the size (height) of the two default tracks
4. Hide the MultiDock and the Bus pane in the Track View
5. Add 78 MIDI tracks
6. Put the first 40 tracks and the remaining 40 tracks into two different track folders (Folder 1 & Folder 2)
7. Collapse only the first track folder (Folder 1)
8. Your screen should now look like this:
http://imgur.com/4Ot03eV9. Select one of the tracks shown in the lower half of the screen (In my case, I select Track 60)
(note: Do NOT scroll down and try to select one of the tracks currently not visible in the screen)
10. In that track, hold Alt and scroll up the mouse wheel to vertically zoom the track for it to occupy the Track View
[Expected Results]
The maximized track occupies the Track View
[Actual Results]
This:
http://i.imgur.com/0juSpWx.png---
And, as I suspected, this also happens when you use CTRL+Up/Down Arrow keys instead of the mouse wheel.