SkinStudio Pro problem - missing skin elements after 'Copy' or 'Save As'

Hi.

I'm a relative noob at working with SkinStudio Pro but have the tutorial PDF and it's been a huge help.  However, I'm experiencing a problem and cannot for the life of me figure out why it's happening.

Ultimately, here's what I'm trying to do:

• Create a new skin only for use on my own PC by using an existing skin created by someone else as a 'base' skin.  Then, I'm trying to change/tweak various other pieces using items from different skins.  For example, changing the titlebar buttons (Min, Max, Close) by using the buttons from a completely different skin.  

Currently, what I'm trying to do is open the skin I want to use as my 'base' skin in SkinStudio Pro.  Once opened, I've tried to select the 'Save As' option so that I can leave the original skin alone and work solely from my 'new', saved skin.  I changed the name to something else and save it.

However, once I do that - and open the 'new' base skin (same as original but with a new name), most - sometimes all - of the titlebar buttons are missing in the preview window and/or when the skin is actually applied to my PC.  What's more, if I try to view each specific button image, they're all there! 

I've also tried selecting the 'Copy' button instead of using the 'Save As' function to see if that makes a difference.  Unfortunately, it does the same thing.

If I open an existing skin in SkinStudio Pro, then either 'Copy' it or use the 'Save As' function - and only change the skin's name - shouldn't I be able to immediately apply the 'new' skin in Windowblinds without any problems - such as the missing buttons I've mentioned above?  Very confusing...

So - what, if anything, am I doing wrong?  Why are all the actual image files copied/saved correctly - and can be seen correctly in the various sections within SkinStudio - but ultimately don't show in the preview window or when the skin is applied?

I've tried reimporting the problem button images but that hasn't worked either.

Any SkinStudio experts out there that can offer some advice/help?  I'd really appreciate it!

FYI - just to be as safe as possible - I want everyone to understand that I'm not trying to create a new skin to call my own by using someone else's work.  I have absolutely no intentions to share the skin in any way.  I'm only trying to tweak an existing skin - which has parts that I don't necessarily like - by changing them using parts from other skins that I do like.  The end result being a skin that I thoroughly enjoy because it uses all the specific pieces of other skins that I liked the most.

I guess you could say that I'm trying to create a 'mutt' skin. 

Thanks again for any help you can provide.

~ DT4eva58