Scott et al.

>  After porting one of my mod_perl apps from 1 to 2, I thought that I
>  had it working but then later found that for some users, POST form
>  data was not available. In other words, when they would submit the
>  form data all of the CGI.pm param()'s were empty even though in my
>  Apache access_log I could see that they had made a POST request. About
>  50% of users were affected and I still have not found a pattern amongst
>  them that distinguishes them from those who are unaffected. GET
>  requests with form data from these same people seem to work fine
>  (although this app needs to POST it's data unfortunately).

Cool... exactly the same thing happened to me, except that it wasn't 
when I switched
from mp1 to mp2 (which I haven't done), it was when I upgraded from 
Jaguar to
Panther, which comes with 5.8.1RC3 and a pre-built Apache/mod_perl.  So 
I'm still
using mp1, yet the exact same thing happens to me; all the POST values 
are lost.

I sniffed around and it seems to be that something is funky with the 
way that CGI.pm is initialising itself under mod_perl; remember that 
when a mod_perl process accesses $r-> args, all future calls to that 
will return nothing.  It seems to me that this is happening too early 
in the case of a POST, but it's not in my code anywhere... so I suspect 
it's buried somewhere in the bowels of Apache and CGI and their 
interactions with each other.

Seems I was luckier than Scott though since I had wrapped all calls to 
get parameters from CGI.pm with a few methods of my own.  To get around 
the weirdness, I just replaced the instance of CGI.pm with an instance 
of Apache::Request, and everything started working again.

Not sure if this helps, but maybe it'll get you on the right track.

Cheers

Kyle Dawkins
Central Park Software