Nero Vision4 help

If some one could please point me in the right direction. I have been looking through the threads and am not sure if I have even looked in the right place. Here is my question:

I have Nero Vision 4(not sure what version) and have been successfully burning dvds for the past two months on 4.7gb sony dvd+r discs. Now for the past week nothing will successfully burn. It either fails after transcoding or the whole program shuts down without any message at all but the process is still running in the background. I have to manually end process. What could have caused this to happen all of a sudden?

Next question is:

If I have a file that is going to take more space than is provided by the 4.7gb I switch the option to dvd-9 and it says that the file will fit. I have memorex dvd+r DL 8.5gb discs for these larger files. I have yet to have a successful burn with these discs. Sometimes it fails after the transcoding process, other times the progress bars fill up making me think that it is working but then just sits there when they are both full. I even waited for 4 hours thinking that it was just having a difficult time with the file and still it was just sitting there.

If anybody has some answers or ideas or maybe point me to some threads that may already exist that has some solutions I would be grateful. Thank you.

Nero is not known for doing DL media very well, If it comes to the case where you need to burn to a DL media use Imgburn in build mode. You will find the link for a guide in my sig.

Have you tried updating?
How many processes do you have running in the background?
How much ram do you have?
Have you tried a fresh install.