not critical as you can always switch tty. In general, typing Ctrl-V
Ctrl-O will restore sane values.
-## Mouse invisble or unusable because moving erratically
+I encountered one time a garbage case on a linux console, which was solved by:
+
+ echo -e \\033c
+
+More details to be found [here](http://www.tldp.org/HOWTO/Keyboard-and-Console-HOWTO-4.html).
+
+## Mouse invisible or unusable because moving erratically
The mouse invisible can happen inside some sophisticated applications
(e.g.: some versions of VirtualBox). The best way here is, after
In nothing of the above solves the issue, restarting the X system may
be needed, see below.
+## Mouse pointer freezed or keyboard unresponsive
+
+This can happen with a USB mouse or keyboard, especially if:
+
+1. You use a KVM switch or
+2. You have switched to a linux console and back to X
+
+Other symptoms: the leds on the keyboard don't change when you hit caps lock,
+or the leds on keyboard or mouse are off. Simply unplug and plug again the device
+can solve the issue.
+
+You can verify after the fact that syslog contains messages about USB disconnections
+of these devices. I know no real definite solution to these issues.
+
## Screen is freezed or blank
Switch to a console, stop cleanly your graphical applications if