I know there are thousands of threads asking for something similar but I'm not able to fix it:

I have Boinc 5.8.16 running in Windows XP SP2 (full patched) and BAM controling all my projects (tanpaku, rosetta, simap...). All of them can connect perfectly but WCG takes out this message:

13/07/2006 20:07:36|http://www.worldcommunitygrid.org/|Sending scheduler request: Requested by user
13/07/2006 20:07:36|http://www.worldcommunitygrid.org/|Requesting 4392 seconds of new work
13/07/2006 20:07:37||Project communication failed: attempting access to reference site
13/07/2006 20:07:38||Access to reference site succeeded - project servers may be temporarily down.
13/07/2006 20:07:41|http://www.worldcommunitygrid.org/|Scheduler request failed: peer certificate cannot be authenticated with known CA certificates
13/07/2006 20:07:41|http://www.worldcommunitygrid.org/|Deferring communication for 1 hr 59 min 28 sec
13/07/2006 20:07:41|http://www.worldcommunitygrid.org/|Reason: scheduler request failed

It doesn't take account name, team and score from the servers. Boinc looks like that:
Screen

I've tried to get out of BAM and attach project manually, dettach it, delete ****.ctr and copy the one you left in some posts, restart project, delete the ***.xml and let the project "remake" it... All things you have said in all threads I've read... but it's impossible.

Have you got any idea of what can be the problem? (I've attached wcg in other PCs in the same LAN without problems and all PCs are receiving units without problem so I guess the router is not the bad guy...)