New User: How to copy and the system error

[myblenderacc]

I am a new user. I want to copy the circle by using relative function:

The first circle is X0 Y0 Z0 and second circle is X0 Y0 Z10

Click Move

001.png (102.81 KiB) Viewed 1013 times

Click the value: X0 Y0 Z10 relative and copy

002.png (90.97 KiB) Viewed 1013 times

According to the youtube tutorial (http://www.hao123.com/?tn=29065018_59_hao_pg), the third circle should be X0 Y0 Z 20:

003.png (99.39 KiB) Viewed 1013 times

Am I do anything wrong?

Second question. The software is always shut down when I click somethings two or three times. I am using 0.13 version (stable). Is it a bug?