ID:2149130
 
Resolved
MouseWheel() had the Y direction wrong.
BYOND Version:511.1357
Operating System:Windows 8 64-bit
Web Browser:Chrome 52.0.2743.116
Applies to:Webclient
Status: Resolved (511.1358)

This issue has been resolved.
Tested this in DS and the Webclient, in DS MouseWheel() delta_y is detected as normal, but in the webclient, it's in reverse. Not sure about delta_x, haven't tested that one out yet.
"511" is not a valid version number in Beta Bugs. I need the full build number.
Edited
Lummox JR resolved issue with message:
MouseWheel() had the Y direction wrong.