Ok, I did a fresh install of WP and installed W3tc with no other plugin…
I still got the same error. I investigated a little… Found this in my apache log
199.102.x.x [15/Apr/2013:12:03:59 +0530] https://www.mydomain.tld – “GET /video/video/wp-content/cache/minify/000000/w3tc_rewrite_test HTTP/1.0” 404 4004 -% 170250us
The issue here is that /video (URI) is repeated twice. (/video/video)
If i repeat the request (with wget) with /video/wp-content/cache/minify/000000/w3tc_rewrite_test i get an ‘OK’ (note single /video )
May be this is a bug ? misconfiguration?