[Plugin: NextGEN Gallery] – HTML 5 validation error

Hi there!
My original template without plugins is clean, everything is OK in HTML validation. But when I installed the NextGEN Gallery plugin my website started to show a mistake

“Line 280, Column 4: No p element in scope but a p end tag seen.
</p>”

I checked in my PHP NextGEN Gallery’s code and I couldn’t see the mistake.
In HTML source I can see “</p>”.

What’s the problem?

Thank you

http://ww.wp.xz.cn/extend/plugins/nextgen-gallery/