Thanks. Solved the problem by checking/creating missing directory.
Another question: For some reason, alot of things that work with my edition of python/pyqt/lxml don't work in calibre (v0.8.6). I keep on coming across the following when running the plugin in calibre:
Traceback (most recent call last):
File "calibre_plugins.ebook_cleaner.main", line 1479, in slotCleanAndOpenEpub
File "calibre_plugins.ebook_cleaner.main", line 513, in clean
File "lxml.etree.pyx", line 2762, in lxml.etree.fromstringlist (src/lxml/lxml.etree.c:52933)
File "parser.pxi", line 1134, in lxml.etree._FeedParser.feed (src/lxml/lxml.etree.c:76722)
File "parser.pxi", line 556, in lxml.etree._ParserContext._handleParseResult (src/lxml/lxml.etree.c:71680)
File "parser.pxi", line 645, in lxml.etree._handleParseResult (src/lxml/lxml.etree.c:72614)
File "parser.pxi", line 585, in lxml.etree._raiseParseError (src/lxml/lxml.etree.c:71955)
XMLSyntaxError: Char 0x0 out of allowed range, line 2, column 1
where the stringlist being input into etree.fromstringlist() is a perfectly normal list of strings (the first three being '<html>', '<head>', '<meta content="http://www.w3.org/1999/xhtml; charset=utf-8" http-equiv="Content-Type"/>' ; these first few strings are written in the plugin, not read from somewhere else; I'm guessing 'line 2' refers to the third one?)
How can I solve this problem?