The only reason I have other screenshot capture tools installed is for scrolling captures.  From my experience as an application tester, I find that each tool captures of a couple of simple setups well for which they seem to have been designed and fails miserably in all other cases.
I tested the new enhancements in screenshot captor v3 against some of the most difficult setups I had to deal with in my job and can  confidently say screenshot captor does scrolling capture *better* than other free and commercial screenshot capturing tools (including snagit which uses a IE plugin for Internet Explorer capture which screenshot capture was able to best by guessing settings correctly even for pages with frames!)

A couple of suggestions:
1. Just like the rest of screenshot captor, there needs to be an (non-default) option for taking screenshots with minimal intervention - an option for always taking scrolling window capture (3) auto-guessing margins and overlaps after selecting the object & ctrl+click
2. Even the vertical (right) side) scroll bars can be trimmed - not sure if it was designed and didn't work only for me

Any luck? I get this message while capturing a firefox window which had '+' (plus) character in the title. It worked when I removed %window title% from the SSC file naming options. Does that say something?