[Zope-dev] Bad Marshal Data

I've asked this before, about a year ago, but got no response. Does anyone else ever see 'bad marshal data' errors sometimes? What are they a symptom of? It sometimes happens in my products, other times in Zope. It always occurs on import statements. I usually manage to fix it by playing around with line spacing, etc, in the module being imported. Deleting *pyc files does not help. Here's an example: Traceback (most recent call last): File "/usr/local/Zope-2.5.1b1-src/lib/python/OFS/Application.py", line 531, in import_product product=__import__(pname, global_dict, global_dict, silly) ValueError: bad marshal data seb