Fabrizio,
I'll split this forum post here, to better track your two existing issues now:
1. The initial discovery problem, which I'm not sure if you were able to resolve yet.
2. Using Active Directory / LDAP integrated authentication for the user account used by the F5 Management Pack discovery wizard.
We'll track issue 2 here:
http://devcentral.f5.com/Community/GroupDetails/tabid/1082223/asg/54/afv/topic/aft/1177053/aff/59/showtab/groupforums/Default.aspx1224599
Feel free to post there any related topic on the user account / LDAP integration.
These two problems could very well be closely related, but for now having the two posts focusing on each individual issue makes better sense for our issue tracking process.
Thank you!
Julian
(F5 Management Pack)