Qt GPL or LGPL Problem

[Archimedes]

LGPL licence on Qt libraries, allows you to link them to a non GPL or LGPL program. That program maybe be free or proprietary software, regardless of what licence you have on that particular program you created. So if you want to produce proprietary soft then you need the LGPL licence. This is the main difference of the 2 licences, they refer to how you can use the Qt libraries and affect also your product (if you choose GPL). At least this is what I understand by reading the licences.
Anyway don't confuse the concept of free software. It has nothing to do whether or not you charge money.