Hi (especially Denis), I've just found an interesting library: Emory Utilities It has a URIClassLoader that fixes a lof of bugs from the JDK version and will work for fixing my problem with the script macros. Doc: http://dcl.mathcs.emory.edu/php/loadPage.php?content=util/features.html#clas... Sources: http://dcl.mathcs.emory.edu/bin/viewvc/software/harness2/trunk/util/src/edu/... Denis, could you have a look and check if it solves the problems you have also solved with your implementation? From what I see it solves most of the pb you have seen and a few others related to special chars in URLs. I just want to be sure your version isn't fixing something more this impl. is not fixing. I'll be trying to use it over the week end but I've already found a way to make it work for my use case (even though these guys didn't know about dependency injection at that time - it was back in 2005...). Thanks -Vincent