[Zope] "import" within external method file doesn't work

Hello all, I've tried to write a simple external method as described a thousand times in the excellent documentation. Within the file "A", I'd like to import another file "B" within the same directory. But when I try to add a function from "A" as an external method somewhere in the tree and try to view the DTML document from which the method is called, Zope tells me that it can't find the module I tried to import in "A". Is this a bug or I'm too much newbie? Any help appreciated alot Christian