[Plugin: BackWPup] Not a valid stream resource

Hi,
BackWPup 1.3.3 and a fresh WP 3.0.1, configured a job with a ftp account to send files, run and after a serie of “added file to zip” start a loop with these:

Warning: ftell(): supplied argument is not a valid stream resource in (basepath)/htdocs/wp-content/plugins/backwpup/app/backwpup_dojob.php on line 78
Warning: feof(): supplied argument is not a valid stream resource in (basepath)/htdocs/wp-content/plugins/backwpup/app/backwpup_dojob.php on line 66

while the report and logs says that all was good, nothing arrived in selected folder, nothing on plugin log folder too.
Any idea?

http://wordpress.org/extend/plugins/backwpup/