What version of Perl are you using and on what system? I had a similar problem with a different module on a particular install of 5.10.1 (a mac running Snow Leopard, and the 5.10.1 that was part of the dev tools). Other installs of 5.10.1 didn't show the problem, nor did later versions of Perl. I never did sort out exactly why it happened. You should try running the test script that fishmonger gave you, and if that fails, try running it on some other installs.
in reply to Error when creating a new instance of XML::Writer