file size problem

I use with a file field imce as a browser for files which are uploaded via FTP. That works great however I have a strange problem. When as user admin (user 1) I can attach from the file system any filesize I want, even those which are bigger than the standard upload limit (in my case it was 64MB. This worked as I hoped for. However when a user with the same profile tries to do the same it give me the error that the filesize is too big (I tried to attach a file of 220 MB) This is not as expected.
I cannot find where this is checked and why it is not checked when logged in as admin.
When I increase the php upload limit the problem is solved but I do not want the user to upload more than 64MB. He should then use FTP to upload and attach the file to the node with the IMCE browser.

Kind of strange that the admin can do it but any other user not? Am I missing a setting somewhere? I use exactly the same imce profile. Hope someone can point me in the right direction.
Thanks