Undefined symbols for architecture armv6: "_xmlFree"

[accessdev]

Hello,

i m getting this error on some machines while compiling my project:

Undefined symbols for architecture armv6:
"_xmlFree", referenced from:
-[MGTwitterLibXMLParser initWithXML:delegate:connectionIdentifier:requestType:responseType:URL:] in MGTwitterLibXMLParser.o
-[MGTwitterLibXMLParser _nodeValueAsString] in MGTwitterLibXMLParser.o
-[MGTwitterLibXMLParser _nodeValueAsDate] in MGTwitterLibXMLParser.o
-[MGTwitterLibXMLParser _nodeValueAsInt] in MGTwitterLibXMLParser.o
-[MGTwitterLibXMLParser _nodeValueAsBool] in MGTwitterLibXMLParser.o

How to get rid of this ?

Thanks