[Tutor] perplexing error with shelve REVISED

[Orest Kozyar]

> It appears you have a cyclic reference in your doc object.  
> Try adding "doc.unlink()" before you add it to your shelf.

Actually, I just realized that doc.unlink() seems to delete the entire XML
content, which kind of defeats the purpose of caching it.  I'll check on
xml-sig and the comp.lang.python group to see if there are any suggestions.

Thanks again for your help!
Orest