Nero 6.6.08a Problems

Hi there first time i have posted so bare with me have used nero from version 5.5 i only recenlty started having problems since updated from to A version, when i create an image it does not let me burn this image because nero doesn’t regonise the file and also when doing my monthly backing up to DVD-rw using continue multi session (UDF/ISO) disc it throughs up error internal error and ejects disc. Does anybody have same problems or any ideas how to go about fixing them.

AMD 64 3200+ skt 939 @ 2350Mhz
Geforce 6800 GT
1024 Gb DDR400 RAM
LG GSA-4163
Lite on 1633
sony CRW 320e dvd rom
MSI Neo2 Plat motherboard