Fixed properties to be private and thread safe

Ignore-this: f5ee3d7f9a67583004fecad2af0814fb

darcs-hash:20121012102849-56b4d-828679e8ed0ddee27d47347dfa528baec8d6477a
Fixed function to be thread safe

Ignore-this: e3ad4ae7195a0f50b892f187ea9661ac

darcs-hash:20121012112924-56b4d-c8544be575cbeb0fa2aa8df5f8d50d6a6a4ac702