not possible to call CI controllers simultaneously?

[eluser]CI beyond[/eluser]
i'm pretty sure the problem is not on the clientside, i don't loop on the client in any way. I only do the xmlhttp call and wait for changes in it's readyState.

apaches access_log only shows the requests after they are complete ( i loop for a limited time in this testingscenario) so they're not very helpfull for seeing if calls arrive on the server simultaneously. I monitor netactivity using firebug and requests are made to the server.

Together with the fact it does work when calling a normal .php file i'm quite sure it's something related to CI. I'll do some additional testing to see if it's anything i've done wrong on my end.