problem joining avi parts

[cellocgw]

Just wanted to make sure I wasn't doing something dumb before I call this a bug.
I tried to join 3 segments of a avi movie (downloaded them as 3 independent files) by loading the 3 files using "browse" and then clicking the Join button. FFmpegx crashed. It turns out ffmpegx properly joins the first two files and then (whether or not there's a third file listed) crashes. I was able to join parts one and two, then join the output to part 3 after restarting ffmpegx, and so far as I can tell got a cleanly joined movie.
So, is this a bug? Is there a way around it?
thanks
Carl

[major]

You can only join two segments at a time.