If you've erased your flash, check out our document on recovering if.
http://support.logicpd.co...rtalid=0&EntryId=778 You will also need to restore the Ethernet MAC address (see Section 6 in the above document) if you want to do any network access.
The instructions are written for Windows, but if you are using the virtual machine or operating under Linx, you can use 'mono' to run the tool in emulation under Linux. If you are using a different port than /dev/ttyS0, make sure you use the -p flag to set the port. Ubuntu 10.04 has Mono framework installed by default.
adam