They are different operating systems and versions of Imager so I don't know.

It is somewhat surprising that you thought the details here to be of so little relevance that you didn't include them. Oh well.

any ideas you have on how to get Imager to use my fonts.

Since you have provided no code at all, perhaps that is where the problem lies? I have just tested align-string.pl with this invocation:

$ ./align-string.pl /usr/share/fonts/TTF/luxisb.ttf 20 string.png Perl
+Monks
[download]

and it has worked flawlessy (after fixing the shebang) on Imager 1.019 here. I suggest you try something similar.