IIS error log

Hi

I have some hardware loadbalancers feeding through to a web farm. They check
every few seconds to see if the webservers are up by sendign a request and
recieving a set reply.

When I look up these requests in the IIS logs i get a strange message.. the
status is 200 but the sc-win32-status = 121 and the time taken is very long.

I have looked this up in google but only found very basic information. It
states that the semaphore timeout has expired.

Reading this I think the problem is that the loadbalancers are not telling
the webservers that the connection has completed?

Can someone tell me if there is any implications or effects on webserver
performance? I take it that at very least IIS must be waiting (about 75sec)
for the connection to close?

Does anyone have any further information about sc-win32-status statuses?

Thanks