Thanks for the additional confirmation and workarounds. Personally, as I mentioned in #12, I'm no longer suffering from this issue because I've been doing horizontal zoom by Ctrl+Alt+scrolling inside the Clips pane.
What I do find inconvenient (but strangely not mentioned by other users) regarding mousescroll zoom is that Ctrl+Alt+scrolling (horizontal zoom) and Alt+scrolling (vertical zoom) that both work in both the TV Clips pane and the PRV Notes pane don't work in the PRV Drum Grid pane. Also, the horizontal timeline zoom (right-clicking on the time ruler in the PRV and dragging up/down) doesn't work in the PRV Drum Grid pane (you guys don't use drum maps by any chance?). I reported these inconsistent behaviors some months ago and Ryan confirmed and forwarded them to development, so I'm hoping they'll also work in the Drum Grid pane in the future.
Also, there's currently no way to vertically zoom in/out ALL tracks in the Track View using the mouse wheel (although you can do it by hitting Ctrl+Up/Down arrow keys or by clicking the border between non-current tracks and dragging up/down). I submitted a request for this as well.