Observe_form, ssl and Internet Explorer

Can anyone help with some strange error messages I’m getting on IE when
using observe_form.

I’ve written some code to observe a set of radio buttons and it all
works
fine in Firefox but when using IE about 20% of the calls return a
request.status of 12152, ERROR_HTTP_INVALID_SERVER_RESPONSE (and the
occasional 12030, ERROR_INTERNET_CONNECTION_ABORTED).

It only happens on SSL pages but client requires this so I can’t serve
it up
on http. I’m using lighttpd on linux as a server.

Googling about I’ve tracked these errors back to wininet.dll but can’t
seem
to find any further info than that. MSDN suggests running the debug
version
of wininet.dll which creates a log of all the calls to wininet but the
logs
haven’t been any further help.

Has anyone else come across these errors?

Any info greatly appreciated.

Cheers,
CL