Where did you et the version of the font installed on the PC? It sounds like you have different versions on the PC and Mac.
[Apologies, this is all new to me] I didn't realise there's multiple versions of the same font?
I got a zip file from work with the fonts - though for some reason, some of the fonts were empty / 0kb. So for these, which included Gotham, I have found what I could legally on the net.
Gotham I found from SomethingDesign.net
How can I make sure I get the same version of the font?
Any thoughts on the first question too?
When you see fonts on PC with 0 bytes it usually indicates that they are Mac format Type1 or TrueType fonts, and they are not usable on the PC. I've been doing some reading, and you might want to as well, at http://www.typography.com/ask/faq.php (particularly item 32), which explains at least partially why you are seeing different names and groupings across platforms. You may see this even with an OpenType version of the font. You should also read the EULA (http://www.typography.com/home/eula.php). Based on the EULA I would not choose Gotham for any work that was going to be distributed electronically.
Thanks Peter - I'll have a read of your links. Any further questions, I'll post back on here. Cheers.