I have recently applied the most recent Windows 2003 RC2 x64 updates and rebooted my server. After this reboot I decided to upgrade 3cx so backed up 3cx and installed the latest v9 (from v8), the installation goes fine and everything starts up. However I found that after restoring my backup the VoIP providers wouldn't register (Sipgate and webcalldirect). After some fault finding I found out that 3CXPhoneSystem.exe was crashing Event Viewer Code: Faulting application 3CXPhoneSystem.exe, version 9.0.13677.0, faulting module 3CXPhoneSystem.exe, version 9.0.13677.0, fault address 0x0025284f. I decided that the backup might have been corrupted so I started setting the system back up manually and when I can to creating VoIP Providers, once saved 3CXPhoneSystem.exe crashed. It only seems that 3CXPhoneSystem.exe crashes when I add a VoIP Provider regardless of the actual provider. My server specs are: Dell R300 Intel Xeon X3363 Quad @ 2.83GHz 12GB DDR2 Ram 2 x 500GB SAS Perc 6I/R (running drives in raid 1) Windows 2003 RC2 x64 (fully updated inc service packs as of 4/10/10) .Net 1.1, 2.0 SP2, 3.0 SP2, 3.5 SP1 3CX 9.0.13677.0 If you require any extra information please let me know. Any assistance people could give would be greatly appreciated.