Hey, thanks for the reply!
It's not the rc-script itself.
The program in question is SoX, the script launches a SoX recording session. If I set recording time to, say, one minute, after the minute has passed, SoX closes itself and login prompt is displayed. In other words, until SoX finishes, it does not proceed to login prompt. Adding & to the end of the line that starts SoX in the script doesn't do anything... unless I'm missing something.
Basically, what I have in the script is this: rec [options] outputfilename [some more options] [recording time] &