Hi Maso,
As also Jukka said, this is a restriction for Basic. Reason is that Basic is only meant for testing, and we do not want people to use Basic for distributable applications. For this reason, unfortunately it's not possible to install multiple instances of Basic applications on phone.
As again Jukka mentioned, if you have a free application, you can request a KuneriLite Professional license (free of charge) any time from the link below. With this license, you can create one application, that users can install without any problems.
http://www.kunerilite.net/content/view/31/48/Please let us know if you need further help.
cheers,
Ugur.-