Use of uninitialized value in subroutine entry

[Erin Young]

I'm going through the circos tutorials included in http://circos.ca/distribution/circos-tutorials-current.tgz and I am running into

"Use of uninitialized value in subroutine entry at /circos-0.69-9/bin/../lib/Circos/Configuration.pm line 781."

I haven't been through all of them, but this happens with all the ones I've tried (1/1, 2/7, 3/2, 4/6, 5/2, and 6/9).

I think I may be missing something with my perl or circos installation. It looks like everything is being rendered as expected, though. Here's the .png from 1/1.