[NTG-context] mptopdf overwrites and deletes pdf file?

Hi, consider a folder containing foo.tex and foo.mp. Suppose that, when compiled, foo.mp outputs foo.1. Then, the following: texexec foo.tex mptopdf foo.mp will end up having foo.pdf deleted. I guess this is because mptopdf creates foo.pdf out of foo.mp *and then* renames it into foo-1.mp. Is it true? Is there a workaround (something like -jobname), other than using different names? Nicola