The PRO version doesn't contain any ads or the LimeShop stuff. That's why you paid for it (and the support also, I guess).

And, if you feel like going back to open source stuff, you might as well stick with LimeWire, since it _is_ open source.

If you install the free version, you're presented with the option of installing LimeShop -- you can always disable it [which I do], and the software isn't installed.