Another reason for "Undefined symbols referenced from"

Failed to add a static library into my iPhone application. Doing everything I've done earlier, searching for new tips on internet, recreating static library project dozens of times - and still:

Undefined symbols:
"_xmlDocSetRootElement", referenced from:
+[CXMLNode(CXMLNode_CreationExtensions) documentWithRootElement:] in libTouchXML.a
ld: symbol(s) not found
collect2: ld returned 1 exit status

Finally found out that even though my version of TouchXML links to dynamic libxml2, I need to link libxml2 with application, too! Expected that once would be enough. Now wondering whether it really will be linked twice.