The theme I use, uses timthumb to generate thumbnails. This causes no issues with your plugin version 3.2.1. When updating to the newest version however (haven't tried the intermediate verisons), something goes wrong with the url it generates. The url passed to timtumb when using version 3.2.1 of your plugin is is something like this:
When using the newest version however it becomes:
So for some reason it adds "//www.example.com" to the src attribute.
Any ideas? Thanks!!