BeginRequest event not fired when using SSL

[Artur]

I'm trying to write a code that will change prefix (http to https and
vice versa). It half works now, because I can reach
Application_BeginRequest method in Global.asax file only when NOT in
secure connection. If I open ay page with http, the methodod is fired,
and if with https, it is not fired. I tried to do the same thing,
creating a module and setting event handlers to BeginReuest event in
Init method, hovewer the Init method is not invoked too, when in secure
mode.
Do you have any ideas why this could happen? I working on Windows 2003
Server with IIS 6.0.
As I see on Usenet and forums, Global.asax's Application_BeginRequest
method is commonly used to solve http/https thing, as well as adding
event handler to Application obiect (creating module), so probably it's
not a general fault. If anyone ever met something like this and has a
solution, I would be very grateful.

Thanks.
Artur