I tried the plugin and I can't see that sitemap created.
I use permalink structure different from the default WP.
Also I currently don't use a robots.txt file.
No other sitmap plugins installed.
If I try to go to site.com/?feed=sitemap I get this WordPress error -
ERROR: sitemap is not a valid feed template.
I use WP3.0.5. and last version of the plugin.
Linux with Apache server.
Are there any suggestions for this?