That can't be right. I am sporting a good 30+ installed apps, + custom mods and hacks that add considerable space, and I am running at 20mb free. I could have more free if I relocated my ringtones.
Install Mobile Monger, scan main memory, and post a screenshot. My first suspect is that your Opera cache is still on Main memory, which is bad.
http://www.freewarepocketpc.net/ppc-...ilemonger.html
Also, run Cleartemp.
http://mobile-sg.com/software/?p=ClearTemp&platform=ppc
Select all options and clear them.