Do you experience problems during downloading?
Check your connection in Status and Interface settings window.
Use Test Server in Config > Servers.
We will probably ask you to do a test using only basic settings.
Do you experience problems during repair or unpacking?
Enable +Debug logging in the Status and Interface settings window and share the relevant parts of the log here using [ code ] sections.
The binary sabnzbdplus package in Debian unstable depends on python (>= 2.6.6-7~), not python (< 2.7). If you were trying to use the Ubuntu ppa with Debian unstable or testing (which isn't too useful as the only difference is the inclusion of betas and rcs in the ppa), try a newish Ubuntu version instead of the older 10.04/lucid, which is the equivalent of squeeze in terms of age.