Just showed up this months... not many, but targets some very large files on my site.
WordPress/2.9.2; http://example.com/wordpress
The example.com changes. 4 different ones to date.
ROBOTS: NO, but does not seem to be a site indexer either.
Pfui
6:31 am on Jun 30, 2010 (gmt 0)
Similar UA below from last March; hit one dynamic file, 403'd every time. Site named in the UA is registered in Chile, hosted by BlueHost in Provo, UT
I figured the named site was probably the source of a link to that file and the UA was link-checking or snap-shotting or whatevering. Glad it/they didn't come back and keep hammering away.