Files uploaded from web have wrong permission

[Staff IDS]

Good morning,

we have plesk 8.30 on CentOS 4.2 :
Version psa: v8.3.0_build83080131.20 os_CentOS 4.2
OS: Linux 2.6.9-78.0.13.ELsmp

All work good until few days ago and the files uploaded from web (php upload scripts)
was uploaded with right permissions: 644
But now the files uploaded have wrong permissions 600 and from web and ftp we got Operation not permitted

Browsing the files from Plesk "File Manager" we can see this details:
- upload from ftp: (Permissions:rw- r-- r--) and (User:idsuser) and (Groupsacln)
- old upload from web: (Permissions:rw- r-- r--) and (User:apache) and (Group:apache)
- new upload from web: (Permissions:rw- --- ---) and (User:apache) and (Group:apache)

The permissions are wrong and we don't know the reason.

We have found this articles:
http://www.dustinsdesign.com/perfect-permissions-for-joomla-and-plesk/
http://rackerhacker.com/2007/05/20/joomla-and-plesk-permissions/

But we don't want change all this settings for a problem started few days ago.

Please, anyone has any suggestions?

Thanks in advance and regards

Staff IDS