This is the perfect solution for my site to increase my newsletter subscribers. It works great in firefox but when you add any html it crashes internet explorer. The html I was using was not complicated at all...one picture no text. If the developer can figure out a way to fix this issue and have an image work I will support him with a beer anytime he wants!
I've tested the popin with images, and it works in my tests. Unfortunately, since the plugin accepts any HTML, and all websites are different, it is hard to actually determine whether the crashing of IE is coming from the plugin per se, or something else!