I got the following error messages from the most recent version of FS from binaries or built from source:

2011-07-10 18:11:41.281250 [ERR] switch_nat.c:200 Error checking for PMP [init failed]
2011-07-10 18:11:46.109375 [ERR] switch_nat.c:257 Bind Error
2011-07-10 18:11:46.109375 [ERR] switch_nat.c:364 Unable to initialize NAT thread

How critical are those errors and how to fix them?

Thanks