I ran into the offset problem as well with the scrollview. The first image in the scrollview was positioned correctly, then if you scrolled to the second image, it was off by 4px. The third image was off by 8px. After 10 images, it would be off by 40px and showing part of the previous image.
My problem was that I used a template to populate the scrollview, and the template rendered the pages like:
<div data-role="scrollview">
<div data-role="page">
...
</div>
<div data-role="page">
...
</div>
<div data-role="page">
...
</div>
<div data-role="page">
...
</div>
</div>
And there was actually 4px space between each page. So if the scrollview was 1680px wide, the offset of -1680 when viewing the second slide was inaccurate, the second slide actually started at -1684.
I finally found out that if I changed the template to take out the line breaks and tab formatting between pages, and rendered the scrollview like:
<div data-role="scrollview">
<div data-role="page">
...
</div><div data-role="page">
...
</div><div data-role="page">
...
</div><div data-role="page">
...
</div>
</div>
Then the offset problem when scrolling pages went away, the pages were the proper width and didn't have the 4px of space between them. Makes sense, but was time consuming nonetheless!