Whenever i compare parses i usually look at the casts timeline to see what my “mentor” cast.
But when i scroll through the timeline it skips over 2 seconds of the timeline. i think the original intention was to create an overlap when scrolling but i think someone messed up +/- 
Do you have an example link?
http://www.fflogs.com/reports/tLGCx9fKWyzBc6w2#fight=2&type=casts&view=timeline
first section goes from 0 to 11.5 seconds, now one tick of my mousewheel moves to 13 to 24.5 seconds.
Hmmm, I don’t see that behavior on my Mac or PC, so must be something mouse-wheel-specific with your mouse settings.
From what seconds to what seconds does it scroll on your end?
Maybe you could make the whole area “draggable” (the scrollbar below the timeline is really small 
)
i asked some colleagues ingame and all of them have this issue.
Hmmm, weird. The scroller is just a third party library, so not sure I can do much about it. I’ll check if they have released a newer version in case it’s just a bug in the library.
What brand/type of mice are those of you having the issue using? I just have a standard Microsoft mouse hooked up to both my Mac and my Windows computers, and these mice behave properly with the timeline on both platforms.
Oh I guess by “tick” you meant a full “page” operation. Yeah it does look like the paging operation is bugged and scrolling too much (e.g., I can reproduce by hitting the PageDown key on my keyboard).
This is caused by the design of the view which is fixing the player or ability names on the left as you scroll, so those ability names are part of the scrollable area. I would have to lift those names out of the scrollable area completely while still making sure they line up perfectly with the lines inside the scrollable area. Tricky.
Even though my mouse is set to “3 line scrolling” the drag event from the function handling the scrolling seems to always scroll “1 page”.
If i check with chrome the function offsets the timeline by a multiple of 904px (at least for the above linked parse)
i input some other offsets and with a multiple of 700px the timeline would always start at 0, 10, 20 sec.
so maybe you can modify the scollfunction to return 700px instead of 904px then it would be fixed