Not sure if this is a bug or not.
Running Ubuntu 12.04 on a netbook (HP Comapq mini 110), recent upgrade from ubuntu 10.
I have just installed version 0.7.2 of Tweak.
Trying to run Apt Cache after having done a series of updates to get to 12.04. Program has stuck at 4845 items identified - given that I have just completed the Ubuntu version upgrades I am not certain if this is a normal number of items to identify or if it is a number larger than originally anticipated.
Tweak has stuck at this number for some time now (over 1 hour). When performing other Janitor functions I did so individually with no problems. If the system is rebooted and Tweak restarted it indicates that their are 4845 items that could be cleaned but it still sticks at this number without the 'clean' button being active.
Tweak appears to be fully functional - I can select all tabs and star.
System memory and disk space are not apparently an issue.
Hope that this information is of some use.
Just used 'Sudo aptitude autoclean' which reduced the number of identified items to 1903. Tweak was then able to complete the process of cleaning these out.