Thanks for taking a shot ....
I am sure this is Fedora / Red Hat specific as I can find all kinds of information on getting Ubuntu working but with all kinds of conflicting Fedora / Red Hat information it leaves me concerned.
But you asked for details and there isn't much and no magic involved
Basic generic pc with a quad core 2.4 Ghz processor and 8GB Ram and 6800xt video card running SL6 64 bit.
Stock Adruino 022 Linux install using Open Java 1.6.0 with the librxtxSerial.so library as shipped with Arduino 022.
To generate the failure:
Open a example project say for example the ethernet web server that displays the analog inputs and compile it and upload it to ttyACM0 and everything is successful.
Now open a browser and point it at the address of the ethernet shield and you get either nothing or a screen of garbage.
Tried resets as per some hints on the forums .. no joy
But run the same compile on either a windows Xp or 7 Virtualbox vm after of course installing the Arduino 022 code and usb drivers
and now you get the desired screen and better than that you can now open a browser on the SL6 box and get the proper display too???
Clearly these VM's are using the shared usb connection as a pass through and being able to access the page from the native box tells me that somehow the compile / upload on the SL6 box is not working properly.
Tried other cables and usb ports of course and no change in behavior not that I would have expected any.
Trying to use links to the native libraries in SL6 instead of the ones supplied by Arduino breaks everything so nothing talks at all.
As does trying to use the SL6 provided avrdude instead of the Arduino provided one.
Just as a test I tried installing Arduino on my 32 bit Acer Netbook running Fedora 12 and got the exact same problem so more than ever I am convinced that there is something in the core Red Hat / Fedora distros that Arduino just doesn't like.
I guess the next test is to fire up a Ubuntu instance and see if that changes anything since there are significant differences between debian and redhat at the kernal level.
One note here:
I can successfully compile and upload code from SL6 and get it to run if it doesn't need to talk to the ethernet shield, in other words building up sample code to talk to a 4 line lcd display works just fine. Since the pins I choose for the LCD conflict with the Ethernet Shield I can not try them at the same time but I would expect it not to work based on the previous experiments. A test I will have to do sometime in the near future.
Since the original tests I have purchase an Arduino Mega 2560 R2 ( since what I ultimately want to do needs more i/o pins ) and I can duplicate the exact same failures and successes so processor board makes no difference.
Thanks in advance for any insights