Audone, Per Knowledge Base Document 107136, this outta do it (indeed it did work for me).
Solution:
To resolve this issue, you need to correct the permissions on the folder /Library/Logs/. The steps for doing so are found in technical document 107039, "Mac OS X 10.2: How to Change Ownership & Permissions Using the Finder".
You should then set them as follows:
* Owner: system
* Owner Access: Read & Write
* Group: admin
* Group Access: Read & Write
* Others: Read only
Notes
1. If you upgraded from Mac OS X 10.1, the Group Access permissions may be "Read only" instead of "Read Write".
2. To verify whether a software update was installed successfully, look for its receipt in the folder /Library/Receipts/.
3. This issue will occur if a non-Admin user is allowed to install via Software Updates. Do not allow non-Admin users to install via Software Update if this issue is undesirable.
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Harv