You've got a dual core processor. Didn't notice before. You need to modify your ePSXe.exe so it runs all its threads on a single core. Check this link:
http://www.quandaryland.com/jsp/dispArticle.jsp?filename=/help/Steves_XP_Games_Corner.htm&articleType=Help!+Page& title=Steve's+XP+Games+Corner
Search the page for "hyperthreading". The fix for hyperthreading will also work for multi-core systems.
Dan