Google Sitemap Errors

Continue to get a fatal error using reliable setup...

[FlipFlops]

I've been running the Google Sitemaps script (the sitemap_gen.py) on an Apache server for all of my hosted clients. One site in particular, which happens to the the largest with the most traffic, is not able to complete the sitemap generation.

Towards the end of the cron-job, I'm getting the following error:

Writing Sitemap file "/PATH/DOMAIN.com/sitemap.xml.gz" with 25713 URLs
[FATAL] Couldn't write out to file: /PATH/DOMAIN.com/sitemap.xml.gz

(The script pulls data from the server's access logs to complete the sitemap.)

I've been checking Google groups and elsewhere, but figured this may be one of the best places to continue that search for an answer.

Has anyone else had this problem? Is there any way to get more information about the error that is taking place?

Thanks!

[FlipFlops]

Anyone with these problems?