PyISAPIe: Exception on RunWSGI Write: WindowsError 1229

[geographika]

Hi all,

I've had PyISAPIe running successfully in production for coming up to 5 years now. 

I'm logging any errors from my Python application and a few times a day the following are recorded:

2015-03-11 11:23:38;ERROR;PyISAPIe: Exception on RunWSGI Write: WindowsError(1229, 'An operation was attempted on a nonexistent network connection') [WSGI:193]

2015-03-11 11:23:38;ERROR;PyISAPIe: Exception on RunWSGI Write: WindowsError(1229, 'An operation was attempted on a nonexistent network connection') [WSGI:193]

2015-03-11 11:23:42;ERROR;PyISAPIe: Exception on RunWSGI Write: WindowsError(1229, 'An operation was attempted on a nonexistent network connection') [WSGI:193]

Has anyone else come across these or any ideas on what could cause these issues? Would it be HTTP connections cancelled from the client-side? Can they be safely ignored?