Knoppix on usb memory, how to free resize partition

Hi,
I'm trying to install software with apt-get to my usb-memory Knoppix, but it says "Write error -write (28 no space left on device)
Knoppix is installed on 2gb stick, and there are plenty of free space
df -h shows:
size used avail
/dev/root 3.4M 24k 3.4M
/ramdisk 396M 3.6M 393M
/UNIONFS 97M 97M 0
/dev/sda1 1.9G 827M 1.1G
/dev/cloop 1.9G 1.9G 0
/media/sda1/
knoppix.img 97M 97M 0
persisten 97M 97M 0

So, can I do something to install new programs with apt-get?

Thanks

Timo Koskela
Finland