Several issues. Ubuntu 10.10 64 bit, Arduino Uno

Hi all, my first post here :).

So straight to the point - I have an Arduino Uno board and I installed the Arduino IDE from the repos. Its version is 0018, but there is slight problem. It just won't start, the error written to the shell is

java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path thrown while loading gnu.io.RXTXCommDriver
Exception in thread "main" java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path

. Ok so far so good, I downloaded 0021 and managed to start it, but boo hoo when I try to upload a sketch to the board usinbg ttyS0 as my serial port there is the following error produced: avrdude: stk500_recv(): programmer is not responding. There was another option for the serial port, it was ttyACM0, but when I try to upload with it it just says it could not find it. Any ideas?

ttyACM0 is the correct serial port. ttyS0 is likely to be an actual RS232 interface on the computer. Version 0018 won't work with the Uno.

The Uno works on Ubuntu 10.04 32 bit providing I stay away from heavy duty serial sketches when the whole IDE will lock up until I disconnect the Arduino. It went through a phase of complaining about the missing ttyACM0 with said heavy duty serial sketch running.