Hmm, did you check to see if the file already had the edits?
My EPG failed to update this morning and the extra debug code has revealed ........
Drum roll .........
Feck all
It looks like whatever happens that stop crossepg from running the external program also fails to run my attempts to debug the code, so in the above code, the crossepg_epgcopy fails and raises an exception, so I trap this and then attempt to run the same command but via strace, this also fails and raises another exception. So it does look like whatever happens to crossepg actually stops any external program from being called and run.
Not too sure what to do next, might try posting on a few forums and see if anybody has any bright ideas.