Bug in IEHtmlWindow?

[Massi]

Hi everyone, I'm trying to use IEHtmlWindow in my application (python
2.5, wxpython 2.8 on win xp). Everything is ok, but I encountered a
problem which also affects the demo. If I make a research on google a
strange message appears, saying (I'll try to translate from italian):

Error during execution.
Do you want to run the debug?

line 29:
error: 'r' is NULL or it is not an object

Did anybody have the same problem? is it a bug?
Thanks in advance for your help.