So, let me explain, I've tested everything again, and this makes me see a little bug in my release but this had NO effect on the skin so it was NOT responsible for your problems.
Anyway you should download the skin again to have the exact same version as me.
First delete the folder foosoft and the file fooSOFT.pui both under the PanelsUI folder.
Then, paste the folder foosoft and the file fooSOFT.pui from your newly download .rar.
Then start foobar, then go to where I said and select fooSOFT.pui on the right under Layout.
Then the skin must automatically applied...
Are you sure you use foobar2000 0.9.5.2 ? Because it do NOT work for earlier version as it is said on the description.
If it still didn't work, can you tell me where exactly are placed the files included in my .rar on your pc ?
Do you see fooSOFT.pui under Preferences > PanelsUI > Layout ?