subrequests do not run all phase handlers?

[Stephen Howard]

I'm issuing a lookup_uri request to launch a subrequest.  I'm getting a 
404 on the subrequest when I get a 200 OK response when visiting the 
same uri from a browser.  My suspicion is that this uri, which uses a 
PerlInitHandler to transform the incoming url, can't be found under the 
subrequest because the Init handler is not being run during the subrequest.

How many of the Apache request phases are run under a subrequest, and if 
not all, then is there a way to indicate that I want some or all of them 
to run?

thanks,
- Stephen