Ok, having sussed that I've got the original frog I've now tried to decode the pcf file and it worked like a dream. The only possibility I can now suggest is that those of you who are having problems are maybe using the frog from the Zygote animals disk rather than the frog that comes with Poser 4. MartinC reckons that the original frog on the Zygote disk used carriage return/line feed, whereas the poser 4 version uses carriage return only. The slightest difference (even one byte) between the seed files used for encoding and decoding would make the resulting obj file unintelligible (that's the whole point of the program after all) and possibly produce an error message, though I would have expected a range check error under those circumstances rather than file access denied. If you really are using the Poser 4 frog as seed file, could somebody who is having problems send me both the pcf and the seed file so that I can see whether the files themselves are faulty. Don't send me the frog file from the original animals disk because I don't have that and therefore don't have a licence for it. You'll just have to trust me that I have Poser 4.