Buffering problem

I'm trying to make php output things sequentially as they're printed/echoed.. No luck. It's buffered to the end of the script, and then it comes on to screen. This is while running Apache2, in a cli session it works fine. The script does *not* have any buffering commands at all. The web server does not have mod_gzip installed. I'm running out of ideas to where to look for this, so can you please give me some pointers? Anders.