Ok. Looks like you can trace the problem down to auth::local::registration::Register. The line is 436 of acs-authentication/tcl/local-procs.tcl, which is the following:
if { [empty_string_p $password] || [parameter::get -package_id [ad_conn subsite_id] -parameter RegistrationProvidesRandomPasswordP -default 0] } {
The ad_conn is throwing the error that disrupts the auth::create_user command. I am not sure if this is a bug or if auth::create_user is only intended to be used outside of scheduled procs.
I will probably comment the line out, since I don't use registration and generate my own random passwords in the import proc.
Anyway, thanks again for the responses. If anyone thinks that I should file a bug report, please let me know.
Thanks,
Chip