I think Drac is having the same problem with 
staying logged in -  I tried to help her but I 
couldn't, so I'm afraid my suggestions wouldn't 
help you either :\  I have animanga on 
the "restricted" site list too, but I stay 
logged in just fine :\

For the record, my current privacy setting is on 
low (though it was on medium before).. and my 
restricted sites are listed as 
http://www.animanga.com and 
http://www.cels.org.  No idea what other 
settings could be giving you a problem.  Do you 
have problems staying logged in on other sites 
too?  Can you stay logged in here if you remove 
the site from the restricted list?