Hi,
by looking at my logs I found this line on sssd_nss.log.

(Tue Feb  7 18:45:35:217396 2012) [sssd[nss]] [sss_dp_get_account_int_done] (0x0010): BUG: a callback did not free its request. May leak memory

Is it meaningful to you? If yes, I'm available to provide all my log files.

I'm using sssd-1.7.0-5.fc16.x86_64.

Marco