[Plugin: NextGEN Gallery] Sidebar widget doesn′t show full thumbs

Hi,

I tried the NextGEN widget to add random thumbs from my nexgen gallery to one of the 2 sidebars, but the thumbs are not all there. I chose 6, for instance, and it shows only 2 and a half. Looks like the rest is hidden under the right sidebar or something.
Theme is “Newscast” .
Any ideas what is happening?
Txs

https://www.ads-software.com/extend/plugins/nextgen-gallery/