Command Line -> outgoing.pl

I'm not sure what this is saying - or whether it's an error or not - but if I run outgoing.pl from the command line a few seconds after running the incoming.pl script, on the odd occasion I get this message...

Not a GLOB reference at /path/to/gmail/admin/GT/Mail/Encoder.pm line 178.

Any idea what this might be or mean?

Cheers
R.