Installer doesn't allow You to use dedicated partition - You need to do it manually.

Background story - when qole created it for the first time, repartitioning was considered hi-tech topic (which was a little exaggerated, to say at least - repartitioning using GUI linuxboxes busted this myth), so he focused totally on using Ed via image file.

To be honest, preparing correct partition layout is one of easiest things, that "power user" can do - I wonder, if adding support for dedicated partitions (i.e., automatically extract image content there, as bonus step for installer) would be much hassle to add into installer?

qole, what do You think? Of course, it would be 100% optional.

/Estel