Sorry for a lack of example on this one, but I figure it\'s easy enough to understand.
I have a fixed background on my site, which is currently implemented like this
Its hard to say without an example but you may be missing width:100%
that should stop any resizing with the scroll bar.
Another way to implement a fixed background on mobile is to have a background div with position: absolute
and overflow: hidden
and all your other background implementations, Then have a content div with overflow-y:scroll;
and set the height of the content div using jquery or any other method you choose to get the window height with.
Check out this JS Fiddle for an example.