IIS7.5 FTP 530 error for Isolated users when Server name is too long

IIS7.5 Causes authorization fail when user tries to authorize as isolated local user when server name is longer than 13 letters.

Looking into logs (default to C:\inetpub\logs\LogFiles\FTPSVC* ) is explaiable.
I have server called DATACENTER-PROS2 (16 characters long). According to FTP logs 

2012-07-31 14:42:28 84.17.2.148 DATACENTER-PROS\shopftp 192.168.43.3 21 PASS *** 530 3 3 

So, IIS7.5 FTP takes only 15 symbols of computer name  ( Letter 2 is missing from logs)
Renaming computer solves the problem.