Can you do a test by placing the gallery widget with the same settings on a page without a template (start form scratch) and check if you stilll get the same behaviour. If yes the problem should be coming from Sitefinity 4.1.1339 release which had such problems and the easiest fix I can offer is to test on a backup of the project to upgrade to some of the service packs for Sitefinity 4.1.
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