NEANISKOS  Forgot to mention that I have v11.4.0 installed already (I checked it before running the update), so that is not the problem. But thanks for your reaction anyway, iSaw.

Needless to say, also, that I haven't changed anything in the location of MS Office, so that's why the message the necessary location cannot be found is puzzling me.

Other suggestions would be greatly appreciated.  
(Version 11.4.1)

NEANISKOS  Trying to run the standalone-update on my iBook G4 10.4.11, I get the message that the standard location that is necessary for the update could not be found. Previously I wasn't able to update the Microsoft AutoUpdate software itself for the same reason. My current version of AutoUpdate says there are no updates. So either way (standalone and AutoUpdate) it's not working. Any suggestions?  
(Version 11.4.1)

NEANISKOS  Well, you're welcome, but the one you should actually thank (and probably worship) is the sacred Panda, of course...  
(Version 7.0.6)

NEANISKOS  As mentioned in other comments, every midnight from Saturday to Sunday the app pops up a biblical quote. As it turns out, in the pop-up window to the left of the quote there's the app's icon: a panda bear clutching a calendar. I find it hard to suppress a giggle when, every week at midnight, the panda bear miraculously makes its appearance and starts prophesying: "And as they went to tell His disciples, behold, Jesus met them, saying All hail. And they came and held Him by the feet, and worshipped Him" (Matthew 28:9), and stuff like that. Oh, holy Panda Bear, lead me into the light of the Lord's grace!  
(Version 7.0.6)

NEANISKOS  Found the answer on my own question: "The new volume sliders depend on a new Cocoa feature for embedding arbitrary controls is menus and so they only show up on Leopard." (developer's website)  
(Version 2.0)

NEANISKOS  Sorry, must have been blind, it's even on the Macupdate description above.

A bit disappointing though: surely adding the sliders for Tiger shouldn't be the most complicated thing in the world. Or is it?  
(Version 2.0)

NEANISKOS  Nothing has changed for me: the downloads, both the one from Macupdate as the one from the developer's website, install the previous version, erroneously tagged 2.0. Anyway, no sliders whatsoever.  
(Version 2.0)

NEANISKOS  I've just installed SoundSource 2.0 on my iBook G4 with 10.4.11, but those new volume sliders are nowhere to be seen. Things look just the same as on the previous version. (Of course I have uninstalled the previous version first before installing v2.0, so there cannot have been some sort of interference).  
(Version 2.0)

NEANISKOS  This little app is fantastic! If it would have the possibility to specify the location where the screenshots are saved, it would be perfect.  
(Version 0.6.1)

NEANISKOS  v1.6a1 crashes when removing all non-favorites

When clicking on the button "remove all non-favorites" in Safariplus v.1.6a1 (on a G4 iBook), the first time nothing happens, the second time Safari 3.0.4 crashes invariably. Apart from that, this beta works fine.  
(Version 1.5.1)