Time shift tool is stucked

[Tengri]

Hello,
(first of all excuse my language mistakes, I'm French!)
I am working on a .aup file with several "blocks" with space between them, and now I am trying to join them using the Time shift tool. It works perfectly fine except for one block, that I am absolutely unable to move.
I closed and re-opened the software, but nothing changed.
Does anyone know what's wrong?
Many thanks in advance.
(Audacity 2.0.4)

[steve]

Zoom in very close on the beginning of the block that won't move and check that there is not an additional very small block getting in the way.
(Zoming: http://manual.audacityteam.org/o/man/zooming.html)

[Tengri]

Thanks. I've done what you suggest, and I see no small block in the way....

[steve]

Can you move the block in either direction, left or right?
Perhaps you will be able to cut and paste the block rather than sliding with the Time Shift tool. To select the block, double click on it.

[Tengri]

I can't move it right nor left.
I hadn't thought about cutting/pasting it, that makes sense!
Just another mystery of Audacity, I guess...
Thanks.

[steve]

I still suspect that there may be a very tiny block in the way - perhaps only a single sample, so you would need to zoom in as far as possible to see it.