I'm going go out on a limb and guess that you've installed one or more non-standard fonts on these machines, right? Normally, this shouldn't be a problem at all, but when dealing with third-party fonts which try to replicate Middle Eastern and/or Southeast Asian scripts (Arabic, Urdu, Devanagari, Malayalam, Tamil, etc), many are hacked up and cause font-cache corruption.
Try the steps here http://helpx.adobe.com/photoshop/kb/t... and then see if these allow your machines to work. If not, try removing any added fonts, especially those obtained for free over the web and which are used for the languages I mentioned.
If you're still having trouble, let us know and we can go from there.