Greetings! I've been working with some of my coworkers tracking a problem very similar to the one described in this thread: http://lists.zope.org/pipermail/zope-dev/2002-November/017922.html which is also outlined here: http://zope.nipltd.com/public/lists/zope-archive.nsf/ByKey/B9323F6D666D3D5C and I've found out some things which may be helpful in finding a better long-term solution. There appears to be a problem with the way that External Methods are inspected when called via XML-RPC. Specifically, mapply() doesn't know what arguments the external method is expecting, apparently because the 'func_defaults' attribute of the object doesn't seem to be set properly. Interestingly enough, if apply() is called then the external method is fully inspected (presumably because it's actually invoked), after which the external method call works properly via XML-RPC. Practically this means that when I invoke an external method via XML-RPC and pass the correct arguments, mapply() doesn't know what arguments the method is expecting, assumes (in essence) that it expects 0, and returns 'too many arguments' (where 1 > 0). However, if I invoke the external method with *no* arguments, mapply() assumes that everything is good and invokes apply(), which throws a TypeError (function expects at least 1 argument, 0 given). If I then invoke the method *again* with the proper arguments (i.e. I use exactly the same call I made the first time), then the object inspected by mapply() has the 'func_defaults' attribute correctly set and the method works properly. I've spent the better part of two days sprinkling LOG() calls throughout ZPublisher, so I can give some more detailed information if anyone's really interested. In the meantime, I temporarily hacked my local copy of mapply() to invoke apply(object, '') for every call, forcing the method to be properly inspected/cached/whatever, then caught the TypeError and moved on to the rest of mapply. This worked for me, causing all of my XML-RPC calls to function properly, but concerned me because it opened the possibility of apply(object, '') being called successfully twice for an object that takes no arguments. So I backed that out and hacked by local copy of publish() instead, calling apply(object, '') for any object whose path matches my external methods. This should work for us without any unintended side effects, but I'd obviously like to be involved with a long-term solution that would benefit the whole community. Please let me know if there's any more information I can give or anything else I can contribute. I'd be glad to do more legwork, but I got bogged down last night trying to unravel the inspection/creation of external method objects, and can't really proceed effectively without some pointers on how that stuff works and where to poke around. Thanks very much, Nathan 'Nato' Uno Hostway Corporation Nathan.Uno@hostway.com