I had this frustration when using my mouse wheel to scroll through event sheet editor. Since Construct 2 allow to scroll only 1 line at a time, I found a little mouse enhancement software that allows to scroll more lines at a time + scroll the background windows (without clicking on them first to make the active ).
STEPS:
1. Download KatMouse from here: http://download.cnet.com/KatMouse/3000-18491_4-24138.html or from any other place (for me, the last version 7 is not working on win7 x64. I am using version 1.04)
2. After installing the software, go to settings ->classes tab and drag the cross icon over the event sheed editor in C2
2a. I forgot about this step. Disable this so you can open links in a new browser tab by pressing middle button
3. Double-click the class name in KatMouse
4.Set how many lines at a time you want to scroll with your mouse wheel
If you have problems when Google Chrome zoom in/out for no reason, you can repeat step 2 but this time drag the cross icon over Chrome, and on step 3 make sure to check "Windows has wheel scrolling support?"
That's it !