NewBie Informix Setup questions

I have installed Informix on my Sun machine (This is Informix 9.0, but question deals with some basic aspects common to earlier versions) After setting up a small pure relational database than ran fine, I tried to load up 2 tables (on a dbspace I defined, Let's call it dbspace1, it is a cooked space ) that had about 1.2 million entries each and a couple of indexes each. Both the tables loaded fine, then I checked my dbspaces, both rootdbs and dbspace1 were close to being full. So I allocated another chunk to rootdbs (cooked space), and a big chunk to dbspace1 on a different external disk (also cooked space). I went on to create indexes, first one finished and very little space was left on dbspace1 at that point. My assumption was that chunks were transparent, which means once I created them, data that cannot be put on first chunk, is automatically put on the next. Well, things did not turn out to be that simple, my second index, which would have hit the first chunk boundary, failed, complaining about "no space left on device" After that I have tried changing my extent size on the table (earlier it was default, now I jacked it up to 50K). Does not help! Only config parameter I have different from default setup is 50,000 locks. What am I doing wrong, Can someone help!!!! Girish