Pathauto doesn't run when it's called

Hi,

I'm having a hard time creating a new node programmatically and getting the right alias set for it. Specifically, after $node->save(), I have two problems:
1) Pathauto is not invoked. It needs to be run manually.
2) and even weirder: calling node_pathauto_bulkupdate() after $node->save() worked for a while - now it doesn't anymore and I have no clue what I did to make it stop.

What I would like to do is:
- create a new node programmatically
- have its alias built automatically by pathauto.

Any help appreciated. :)

-Tobias