https://github.com/mlaws/solidoodle2-marlin

says that Arduino version 0022 is no longer required. Instead, you can use Arduino 1.0.5. So I downloaded the Linux version and copied all the Arduino add-ons from the above link (in order to use the board Sanguino W/ ATmega644P). Everything seemed to be going according to the instructions until I tried to upload the firmware file (Marlin.pde): all I got was
the error message "avrdude: stk500:recv(): programmer is not responding." Anyone know how to fix this? Thanks.

Sounds like you're headed in the right direction, but you might need instructions from someone who's done a solidoodle firmware upgrade from linux before though.

As far as I know, you should be able to run the arduino program you installed with apt-get by typing just "arduino" into the command line...

http://wiki.solidoodle.com/update-firmware

But I'm stuck  at the point where it says

Start arduino.exe and go to Tools, Boards, and select either "[USBtinyISP]Teensylu/Printrboard" or "[BootloaderCDC]Teensylu/Printrboard]"

I'm a Linux newb, and I don't know how to start arduino.exe. I made it executable using chmod +x arduino.exe, but when I try to execute it, I get the message, "unable to find an interpreter for ./arduino.exe."

I tried getting the latest Arduino software for Ubuntu by typing: sudo apt-get install arduino arduino-core, but this does not solve the problem. Thanks in advance for the help.

Connected simply means the comport opened.. Not that its communicating

Recompile the firmware, screw with Linux to make 250000 work, or use Windows.

I tried setting "Reset on Connect" to "Disabled," as in the link you suggested rjp350z, but I still got no response from the printer. And I tried clicking the "OK" button in the debug options of the Manual Control window, but that didn't help either.

Nor did first hitting the reset button on the printer motherboard (just to be sure--it's just the black push-button in the upper-right corner of the board, right?).

Anybody have any other ideas? I may just have to resort to Pronterface...

Oddly enough my reset solution sounds to be the opposite of the above poster's suggestion.

http://www.soliforum.com/topic/5758/repetierhost-v095f/

However, after connecting, the Solidoodle is completely unresponsive. When I try to move the printer head, all that happens is the number in front of "Command Waiting" increases. Furthermore, the temperatures of both my extruder and printbed are listed as 0 degrees. I don't think there is anything wrong with my electronics board because, as I said, everything worked perfectly before I switched to Linux.

Looking at some of the posts on the board, I'm wondering if this could somehow be a firmware issue (though I have no idea how that works). Thanks in advance for the help.