Remote Desktop causes system to think ctrl and alt are pressed

Let me run through the process to make sure I have it strait:
1) Start vncviewer (on client pc)
2) connect to vino (on server pc) from client pc
3) login, etc
4) sometimes ctrl-alt act pressed (Does this happen immediately???)
5) push ctrl-alt and everything is back to normal?
6) logout
6b) walk over to the server computer
7) login from the actual server computer
8) sometimes ctrl-alt act like they're pressed at the actual server computer

Just to clarify, you ran vncviewer from the command line on the client side? What version is it? Am I correct in assuming that the client machine is not running Hardy (as there is no default vncviewer install)?

If you run dpkg -l vino, what is the version number listed there? (2.20.0-0ubuntu1?, 2.21.90-0ubuntu1?, other?)
how about dpkg -l xvnc4viewer? (4.1.1+xorg1.0.2-0ubuntu6?, other?)

Thanks for the help getting this sorted!

Steps 1-3: Accurate.
Step 4: I believe it is always initially, but sometimes I reconnect repeatedly for different reasons and I can't recall for sure if it is always immediate.
Step 5: Yes, pressing crtl and alt have always fixed it.
Step 6: Accurate
Step 7: Computer is already logged in.
Step 8: Seems to be pretty common to find it has happened on the server after it has happened on the client.

Yes, I run vncviewer from the command line. I'm not sure what version it is at the moment, but I would assume whatever the version available from each of their respective repositories (I can check for sure if necessary). I run it either from school which is currently running the last LTS, which I believe is 6.10. Or my laptop which is running 7.10. Both seem to behave similarly (though for some reason I seem to have issues with the new -lowcolorlevel flag not working, but I suppose that's another issue). So no, neither is running Hardy, but I have installed vncviewer from the repository on my server (Hardy) as well (not that it's probably relevant).

Not sure if all the output is useful, but this is the result of dpkg -l vino:

Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-f/Unpacked/Failed-cfg/Half-inst/t-aWait/T-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name Version Description
+++-=================-=================-==================================================
ii vino 2.21.90-0ubuntu1 VNC server for GNOME

and dpkg -l xvnc4viewer prints out the same as above, but with the last line as:

ii xvnc4viewer 4.1.1+xorg1.0.2-0 Virtual network computing client software for X

I will try to start paying more attention. It's been something I've kind of ignored for a while because since I've discovered how to make it stop, I have mostly been ignoring it. Please let me know if there is any other information I can provide to assist you. I will make an effort to see if I can reproduce on demand, but at present, no discernible pattern or reason has emerged that I can see.

I've been trying for a while, but I haven't had any luck reproducing this problem. Is there anything unique about your server or setup that could help? Is there anything different about the IO devices on your server...like a special keyboard or something?
Do you see anything abnormal in the terminal window you started vnc viewer from? Could you try logging this output during a session where the problem happens?
From the command line type:
vncviewer [your_computer] > output.txt 2>&1
Then you could attach that file here....you might want to scrub it of identifying info first.
Thanks!

On some computers I use, vncviewer treats alt+tab as remote machine input and alternates between applications on the server, on others, alt+tab alternates between apps on the local computer and effectively disrupts vncviewer input so that input then goes to the terminal. This also makes it possible to kill vncviewer using ctrl+c (which is normally how I exit vncviewer). I realized that I use both ctrl and alt in this process and it is my belief that those key presses aren't being registered as released. Though I cannot easily duplicate the exact circumstances that cause this on a day-to-day basis, I CAN duplicate this problem using more contrived methods:

1. Connect to server from remote computer.
2. Press and hold ctrl or another key on the remote computer.
3. While holding the key, forcibly terminate the connection (such as unplugging the network cable).

This will cause the server to believe the the key is still being pressed. If you then try to input anything through server, or by reconnecting client, you will find that it still thinks that key is pressed until that key is explicitly pressed on the keyboard and the system registers its release.

Hope this helps.

Ok, I was now able to re-produce this.

After logging into the server from the client, I held down ctrl and un-plugged the ethernet cable. When I then typed into the server machine, ctrl was pressed. This continued even after I disconnected the client by (on the server) right clicking on the remote connection screen icon, and selecting Disconnect [MyIP].

Thank you for your bug report. The issue is an upstream one and it would be nice if somebody having it could send the bug the to the people writting the software (https://wiki.ubuntu.com/Bugs/Upstream/GNOME)