"Page cannot be displayed"

[Bob_Loblaw]

A few of my users are occastionally getting the above message for certain pages. Reloading the page then allows them to continue but the $_Post vars seem to be at least partially absent.

1) Is there anything I can do to see what is causing the "Page cannot be displayed" message?

2) what can I do to ensure my post vars make it through a page reload.
(This only seems to happen with internet explorer. Don't know yet if that is a coincidence or not)

THanks.

[DoctorWho]

Error and Access files for apache, if you are running apache may help.

Ensure all variables are making it too the next page, echo them out.

That's all i got for now.

[Bob_Loblaw]

unfortunatley, the code is on a hosted site so I do not have access to the apache log.