Thanks Vinyl, but the problem persist. The funny thing is that if I spider that site from another host (say, my local PC), it spidered it nice.
I've read that by uncommenting some line at robot_functions.php, you can print the HTTP responses. I'd like to do that in order to do some debug, but I can't find that line in the code. May it be I'm using the version 1.8.3 and that thread is kind of old? How can I print the HTTP responses, and any other stuff that I can us to figure why it stops spidering when phpdig and the site are in the same host? Thanks