Strange behaviour with subdomains

[kadoudal]

Strange behaviour with subdomains - more !!

I had to delete my trac installation, I deleted the trac subdomain I was using.. the domain and subdomain..
all deletions performed within Plesk 8.2

if I check the urls :
http://www.aelmat.net/ => Server Default page
http://stage.aelmat.net/ => Server Default page
http://dev.aelmat.net/ => Server Default page

BUT

http://trac.aelmat.net/ => time out..... idle !!

I cannot understand why ??
I should get ALSO a => Server Default page

is anything left in cache or any update not performed by Plesk

--- I reinstalled my box (Debina 4 & Flesk 8.2.1) from SCRATCH... the domain
www.aelmat.net
the subdomains ( dev, stage, trac)
and still got
http://trac.aelmat.net/ => time out.....

the favicon is the Trac one... is there any kind of 'registration' somewhere ???