solution for this case is to make tftp server availble from data VLAN. in defaul config file you have to add statement:
<Enable_VLAN>Yes</Enable_VLAN>
<VLAN_ID>77</VLAN_ID>
unfortunatly phone after receiving that file doesn't reboot so you have to reboot it manually (for examle toggle on/off PoE on switch)
77 - voice VLAN ID in my case please feel with your setting