Thread-safe access to permanent store

Hello!
How can i access to my store (i am using file dictionary store) from 
multiple threads?

I use auto-shared session to file server + access thru critical section, but 
have such trouble:
when i call commit for store my programs hangs from time to time...
where is bugs?

P.S. I find this things in emulator s60 plat2 fp1-2...