I have been using CCleaner under Windows XP SP2 and had Installed Nero and Office 2003. Now that softwares Nero and Office 2003 have been uninstalled. I don’t know which version of Nero it was and I have reinstalled different version of MS office i.e. Office XP.now the problem is that even the software has been uninstalled this is shown as applications that are present in Cleaner->Cleaner Settings->Applications.
Is it the problem of incorrect registry entries or problem of CCleaner? If it is the problem of registry entries what shall I do? Is it a bug ?

Sometimes when you uninstall programs, it doesn't remove everything, mostly the registry entries. You will need to delete the registry entires of that program you uninstalled for them not to come up in CCleaner.

So, why doesn't ccleaners issues scanner pick them up and clean them out, I wonder ?

I run Office2000, never installed newest versions,
but CCleaner detects both Office2003 and Office XP.

Same problem with all registry cleaners man . I have also used Registry Mechanic which same problem. doesnt detect all keys especially related to serial keys .