SCID website just provides you the source code, to install it in ubuntu, you need to compile it on your own (like linking other necessary codes).
The following tutorial helped me:
https://plus.google.com/+TedSummers/posts/CKAXosobyGH
Do as it says from the start, dont miss a step.
It will take time, & you need to be very precise.
Hope, this helps.
For me, right-clicking on the board doesn't seem to bring up a menu. (Windows user here). But OPTIONS - GAME INFORMATION and then checking or unchecking TOGGLE COORDINATES works for me.