So I did some tests. Tried the one from Handrawn but I got the message that certain transparencies could not be translated to bitmap so the end result would not be the same. (@Handrawn: I use layers - lots of them )
So, I moved the file to my laptop that has 16 GB of RAM and that generated well, so it is definitely a memory problem. Since my main computer has only 8 MB I am going to get me some extra RAM to solve the problem. In the meantime I'll use my laptop for the export.