Forms built using VB6 used in a DLL used by Excel
 

I have been building a number of forms for an application. Much of the
code has been placed in a DLL.

I set up my forms diligently to ensure the font size and spacing, etc
looked good and was readable, and that frames, labels, etc were big
enough to contain their contents.

However, when I use the code on a different PC, I find that parts of
my labels fail to display - the containing rectangle isn't big enough!

What have I done wrong, and more importantly, how do I put things
right?

I suspect that this is a really basic error. Can anyone help please?