Adept package installer not working if not launched by package manager
I am running gutsy.
I don't understand if I am doing something wrong or if there is a problem with the package I downloaded.
When I install sw using apt-get command line, or adept package manager, everything is OK.
But for some sw that I don't find in the repositories, I downloaded the installation package (.deb file explicitly indicated for Ubuntu/Debian). I did it for acrobat reader and limewire.
I doubleclick on the file, the adept installer pops up, I push the button "install", I get asked for the SU password, and it begins working. Everything seems to go well, because I see the HD light flashing, so I imagine that it is installing something. After a while, however, without giving any diagnostics, the program terminates but NOTHING HAS BEEN INSTALLED.
I tried to serch manually the files listed in the package description, and no one is present on my HD.
Does anybody have a suggestion?