Passing this on to those who are not already aware:

Gallery images require 'safe_names'. I've a client who has created 100+ galleries - their first user understands the naming convention and uploaded the first 50 odd galleries without a hitch. The second user is a wee bit computer challenged and has uploaded the remainder of the galleries with all sorts of characters/spaces in the image names... (a few hours of renaming and FTP uploads await!!)

So far we have found that the following cause the thumbnails to fail:
brackets ( ), spaces, brackets [], and possibly hyphens - .

HTH
Regards

check this out
quite possibly one of my favorite utils

www.bulkrenameutility.co.uk/Main_Intro.php

Thanks for sharing.

You may be interested in this AIR app - I'm installing it for end users who have to interact with K2 Galleries - it'll allow drag and drop batch resize, renaming and then zip everything up for them. Depending on the end users computer savviness, it has worked well... ;-)

Developers site: www.psyked.co.uk/ it's called ImageSizer.

Mark