Meh.. New here myself, and unfortuneately have had a similiar experience to yourself. I'll be of what help I can though. Simply put, it might not be any of your plugins or your emulator at all, but your computer itself, which I'm pretty sure is my case(its still not fully resolved). More or less, try getting an ISO from elsewhere if you can, I won't say where though. For the forums sake, some way that is legal =P Anywho, once you find your legal game .bin file and .cue file (just the file types that are associated with the ISO image), put them into a folder.
Then, go into ePSXe, File> Run ISO, and then select the .bin file(the larger of the 2 files). Hopefully, if your case is similiar to mine, you will be able to play the ISO game that you acquired legally. If not, check back here. Trouble shooting this in a logical manner is the best though, just go down a mental(or written) list of possible problems/solutions and what seems probable. Of course, that hasn't resolved all of my issue(yet).