Bug in ntriple import

I find a very simple to replicate bug.
1) create a simple project with a literal containing a duble quote.
2) export in ntriple format.
3) re-import the same file (with replace)
The error is:

----Importing RDF-----
XMLManager.parse(C:\IsaViz\temp\isv36295.svg): org.xml.sax.SAXParseException: Attribute name "duble" must be followed by the ' = ' character.
RDFLoader.load() java.lang.NullPointerException
Please verify your directory preferences (GraphViz/DOT might not be configured properly), your default namespace and anonymous node prefix declarations

In attach the ntriple example file. (export - import).

Nicola