It shouldn't be corrupt to start with. Rather than trying to fix an ISO through hex editing, just try re-dumping the game, save way more time.
.:Intel Core i7 Extreme 965 OC'ed @ 4Ghz - EVGA X58 SLI - Corsair 6GB @ 1600Mhz 9-9-9-24 - 2xEVGA GTX 285 1GB OC'ed @ 680/1548/1270Mhz in SLI - Dell UltraSharp 24" - Corsair HX1000W PSU - Noctua NH-U12P SE1366 - Antec 900
.CZ Vertex 250GB SSD 200/160MB/s read/write - Samsung F1 1TB
.:Windows 7 x64
.CZ Vertex 250GB SSD 200/160MB/s read/write - Samsung F1 1TB
.:Windows 7 x64