Problem is (at least in my case), whenever using "Lock Zoom", the fuction of "Reset X/Y" is disabled. It's still checked in the options (and even gets "reactivated" as soon as I disable "lock zoom"), it just isn't being used.
I've noticed issues with reset x/y right when I started using the program, and didn't know what was up. (I even made a topic and didn't want to admit the Reset X/Y wasn't working because I tried it already) I eventually figured it out a week or so ago the problem.
...now I'll look like a complete idiot if this is already known or just a problem I'm only having. (or even worse if there are separate options for "Locked Zoom" mode that I didn't know about. XD)
I'm using Windows 2000 Pro SP4 and XnView v1.92.1
Here's a video showing what I mean. (the quality is kinda crap, but it gets the point across. It's not like it's Crysis

http://hostfile.org/XnViewBug.swf