[Exim] expand after pam

Hi! I'm new around here...

So, my little problem, if someone could say something...
I'm using 4.10 running with uid and gid 8/12, with pam authentication. After I
try to login with smtp and using the "login" authenticator, the pam session
successfully ends as the report of exims straced run says but anyway, exim
forbids login while saying this:

11827 write(2, "PAM error: Permission denied\n", 29) = 29
11827 write(2, "login authenticator:\n", 21) = 21
11827 write(2, " $1 = user\n", 15) = 15
11827 write(2, " $2 = password\n", 21) = 21
11827 write(2, "expansion failed: Permission denied\n", 36) = 36

expansion failed....
any idea?
thx!
--
Jáger Sándor
science@???
ICQ: 47054653