1.  open /usr/lib/python2.5/site-packages/GDebi with root account

2. open SDInst.py with leafpad

3. change “LOOP_FILE_SIZE = 256”   to what you want . such 512 ,1024 ,unit is MB

4.once  you installed software,you will have a 512MB space for software

5. you can find software at /mnt/loop/share/applicatio ns/

[from zhiqi fans]