Followup to question about $_POST

I found this thread: Error_page and log_not_found in nginx 0.7.8 - NGINX - Ruby-Forum
So, apparently, using the error page to reroute /mycontroller/mymethod
URLs, does not forward the $_POST array.

I don’t really understand how to use the patch, and I wonder if the
patch is still recommended? Since it was from last August…

/mycontroller/mymethod is very common across many PHP MVC frameworks.
Is using the “error” directive really the appropriate way to do this? I
tried going back to:

location / {
if ($request_filename !~ (js|css|images|robots.txt|index.php.) )
{
rewrite ^/(.
)$ /index.php/$1 last;
}
}

also tried
location / {
if ($request_filename !~ (js|css|images|robots.txt|index.php.) )
{
rewrite ^/(.
)$ /index.php?q=$1 last;
}
}
both of these methods are recommended on CodeIgniter forums, and I had
them working previously with nginx 0.6.33

…and now I get 404…