Hi louis-m,

It worked when I tried it with a setup similar to what you've got - I had to add UDP 53 for DNS.

i was only playing around with it for the orginal poster to see if it worked.
we use untangle for our comercial stuff although for a small company, this may fit the bill. having said that, we also use opendns for our remote offices.
when you say you added dns..... where abouts (posistion, rule) did you add that?

As an extra object to the group in the 2nd firewall rule

action = "pass" UDP 53, TCP 80, 443 & webfilter> "block ALL" profile

nice one! it's working now just by simply putting the dns rule in.

confirmed by changing rulesets etc.
well done macavity and hopefully others who have had this issue follow this post.
symptoms are slow loading/applying (timing out) of the filter if set to block.

lol......
on further inspection my url content filter now appears reversed!!

so, exactly the same rules as above.
1. no web content filter
2. url filter profile> block hotmail
3. in allow filter rule> url filter > block hotmail

the url block rule "block hotmail":
1. when set to block, it allows hotmail
2. when set to pass, it blocks hotmail

strange......

3.3.2 RC5 is available on
http://www.visus.pt/mirrors/draytek/Vigor2820/Firmware/3.3.2_RC5/
if anyone wants to give it a go. Mines been running it now for 88hrs without a hiccup.