[development] strange beavhior after node import

[luca capra]

Hi all,

I've built a simple parser to import downloaded webpages with attchments 
as drupal (6) node.

It's called with hook_cron() and works the most of the times.

But, some nodes get correctly saved in db tables node, node_revisions, 
and other cck tables but if I try to see them  in the browser, as 
example, www.domain.tld/node/1700 I get a 404 error.

I know those nodes get error, because there isn't any attachment (and no 
reference in files nor upload table).

To import nodes I do: (ini_set-ted memory_limit and timeout to proper value)
1  save the file attachment with drupal_write_record('files', $file)
2  node_save with a custom populated array, and the file objects from 1
3  drupal_write_record('upload', $fileinfo, 'fid') to update the 
description that sometimes result empty

I've put a lot of watchdog() everywhere, but nothing. If I run from 
drush or "by hand" It seems to works...

Can somebody give me some hint?


Thanks in advance.
Luca