Sorry for bumping this old thread, but I have a very strange issue with Yuri's Revenge for which Google provides absolutely no answer.
So basically, all new unit voice lines and sound effects don't play. By new I mean the ones introduced with Yuri's Revenge. For example, the regular GI still says his lines and you can hear him fire his weaponry, while the Guardian GI is completely silent. Units with updated voice lines have a similar issue, like the IFV and Mirage tank. Literally everything else works fine however.
Thanks in advance.