I can not install the latest XML package V3.9-4. I mannually install it in RGui by typing:
install.packages(\"LOCALDIR/XML_3.6-0.tar.gz\", repos=NULL, type=
This is a bit of a punt but I had a similar problem some time ago and it was something to do with having another version of iconv.dll (?) available. I think my rogue version came via cygwin. Making that version unavailable fixed the problem.
P.S. I am on Windows and have XML installed. Just from the straight binary.