Question: On my Xubuntu 13.04 installation, when the sound is turned up to high levels (>50%), it begins to (randomly?) fluctuate between loud and quiet. In pavucontrol, the port setting is fluctuating between "Analogue output" and "Headphones" (I'm using desktop speakers plugged into the integrated audio line out).

Any ideas?

Answer: 
There *is* a simple binding for "Select all" in gtk: `C-/`

It’s defined as a general [GtkTextView signal](https://developer.gnome.org/gtk3/3.4/GtkTextView.html#GtkTextView-select-all) and not specifically part of the emacs key theme. But it works fine with it. It's defined as an alternative to `C-a`. While the latter gets reinterpreted by the emacs theme `C-/` remains valid for "Select all".
If you want to select all text in a region, I prefer defining a simple Macro for that.
Press **F3** for starting to write a Macro. Then type

```
Esc - <          // goes to beginning of document
Ctrl - spacebar  // set mark
Esc - >          // selects all till end of document

```

Then use **M -w** for copying (which is what I normally do for copying from remote unix systems to local Windows) and then press **F4** to finish defining the macro.

Now you are done defining the Macro, just hit **F4** as many times you want to repeat the action.