First off, great plugin!
However, I have the following issue that, according to the changelog, is fixed back in v. 1.3:
= 1.3 =
* Fixed issue where only last row appeared when scrolling left.
When scrolling left, all LIs in top row get an opacity of zero. According yo Firebug:
<li class="fpg-item fpg-first-col" style="opacity: 0; margin-top: 3px;">...
When clicking on the pip to load the left page, everything is OK.
Using v. 1.7 on WP 3.3.1 installation.