Thanx guys, i think there is something unstable about the rest of the script, i'm getting other problems too.
There is nothing in menu() or title() except print statements so they cant be the problem.
I'm also getting readline() on closed filehandle main::FILE errors when another option is chosen from the menu. It seems to be pasting the results of the last file read into the filename of the next file :-)
looks like i've really messed this one up :-)