Try making sure that there are no keymoves or macros assigned to the Vol- button.  In TV mode,
1) Press Setup until 2 blinks
2) Enter 994 (2 blinks)   [this is the keymove command]
3) Press Vol-
4) Press Vol- again
The remote should blink twice.

1) Press Setup until 2 blinks
2) Enter 995 (2 blinks)  [Macro command]
3) Press Vol-
4) Press Setup until 2 blinks
The remote should blink twice.

9XX commands instructions