mod_security and false positive?

[upsforum]

I have this rule that block any ip of my customer, but is a false positive? I don't understand what do it

Access denied with code 501 (phase 2). Match of "rx ^((??:POS|GE)T|OPTIONS|HEAD))$" against "REQUEST_METHOD" required. [file "/usr/local/apache/conf/modsec2.user.conf"] [line "38"] [id "960032"] [msg "Method is not allowed by policy"] [severity "CRITICAL"] [tag "POLICY/METHOD_NOT_ALLOWED"]

 

[upsforum]

These are actions that trig this rule of modsec:


37.XXX.XXX.194 - - [27/Nov/2013:11:18:55 +0100] "PROPFIND /foto%20450_bis2_2.jpg HTTP/1.1" 404 - "-" "-"
37.XXX.XXX.194 - - [27/Nov/2013:11:18:55 +0100] "PROPFIND /foto207.jpg HTTP/1.1" 404 - "-" "-"
37.XXX.XXX.194 - - [27/Nov/2013:11:18:55 +0100] "PROPFIND /foto%20450_bis2_2.jpg HTTP/1.1" 404 - "-" "-"
37.XXX.XXX.194 - - [27/Nov/2013:11:18:55 +0100] "PROPFIND /foto207.jpg HTTP/1.1" 404 - "-" "-"
37.XXX.XXX.194 - - [27/Nov/2013:11:18:55 +0100] "PROPFIND /foto%20450_bis2_2.jpg HTTP/1.1" 404 - "-" "-"
37.XXX.XXX.194 - - [27/Nov/2013:11:18:55 +0100] "PROPFIND /foto207.jpg HTTP/1.1" 404 - "-" "-"
37.XXX.XXX.194 - - [27/Nov/2013:11:18:55 +0100] "PROPFIND /foto%20450_bis2_2.jpg HTTP/1.1" 404 - "-" "-"
37.XXX.XXX.194 - - [27/Nov/2013:11:18:55 +0100] "PROPFIND /foto207.jpg HTTP/1.1" 404 - "-" "-"
37.XXX.XXX.194 - - [27/Nov/2013:11:18:56 +0100] "PROPFIND /foto%20450_bis2_2.jpg HTTP/1.1" 404 - "-" "-"
37.XXX.XXX.194 - - [27/Nov/2013:11:18:56 +0100] "PROPFIND /foto207.jpg HTTP/1.1" 404 - "-" "-"
37.XXX.XXX.194 - - [27/Nov/2013:11:18:56 +0100] "PROPFIND /foto%20450_bis2_2.jpg HTTP/1.1" 404 - "-" "-"
37.XXX.XXX.194 - - [27/Nov/2013:11:18:56 +0100] "PROPFIND /foto207.jpg HTTP/1.1" 404 - "-" "-"

PROPFIND is for webdav service? is normally that modsec block these requests?