OK, double check the tick box is ticked to allow galleries to be serach – just seems to ignore it – sorry. Not the bext PHP programmer so please excuse me but did this with the search form and got no results at all:

<form role="search" method="get" id="searchform" action="”>

By the way you refer to th gallery file as ims_gallery. When you install it the file is _imsgallery – tried renaming this to your note but no luck. Any thoughts? Thanks.