If you open windows media player, then tools, options, filetypes. Then check the files you wish to associate with windows media player. I know it still opens with it but, just check that mps files are checked.
The will also be an option for winzip with this.
If this doesn't fix the porblem go to control panel, folder options, then the file types tab. Then scroll down to the file types you need to change, click change and choose the program to open it with.
I think that the file icons you have in your screen shot are probably the default icons for those files. So something you did, or something just happened which restored the default settings for those icons.
You can use this program to resotre all default icons, but this will change any file types you have customized yourself, so it may not be the best option.
However icon packager is actually a very good program. I use it as well. Different icon themes to be used with icon packager can be foun here http://www.wincustomize.com/Skins.aspx?LibID=2 for anyone who wants to use it.