On Tue, 19 May 2009, Jeremy Huddleston wrote:

press right:
May 19 18:01:14 aeris kernel: [  256.453247] drivers/hid/hid-core.c: report (size 8) (unnumbered)
May 19 18:01:14 aeris kernel: [  256.453259] drivers/hid/hid-core.c: report 0 (size 8) =  00 00 4f 00 00 00 00 00

[ ... ]

press down:
May 19 18:01:17 aeris kernel: [  259.429256] drivers/hid/hid-core.c: report (size 8) (unnumbered)
May 19 18:01:17 aeris kernel: [  259.429268] drivers/hid/hid-core.c: report 0 (size 8) =  00 00 4f 51 00 00 00 00

[ ... ]

press left:
May 19 18:01:20 aeris kernel: [  262.469256] drivers/hid/hid-core.c: report (size 8) (unnumbered)
May 19 18:01:20 aeris kernel: [  262.469269] drivers/hid/hid-core.c: report 0 (size 8) =  00 00 01 01 01 01 01 01

[ ... ]

release right:
May 19 18:01:22 aeris kernel: [  264.981247] drivers/hid/hid-core.c: report (size 8) (unnumbered)
May 19 18:01:22 aeris kernel: [  264.981258] drivers/hid/hid-core.c: report 0 (size 8) =  00 00 51 50 00 00 00 00

[ ... ]

release down:
May 19 18:01:25 aeris kernel: [  267.405254] drivers/hid/hid-core.c: report (size 8) (unnumbered)
May 19 18:01:25 aeris kernel: [  267.405267] drivers/hid/hid-core.c: report 0 (size 8) =  00 00 50 00 00 00 00 00

[ ... ]

release left:
May 19 18:01:26 aeris kernel: [  269.277246] drivers/hid/hid-core.c: report (size 8) (unnumbered)
May 19 18:01:26 aeris kernel: [  269.277258] drivers/hid/hid-core.c: report 0 (size 8) =  00 00 00 00 00 00 00 00

Looks like the state machine inside the keyboard gets a little bit crazy 
when you press the third button. The data that HID core sees coming on USB 
bus really don't represent [right,down,left] being pressed.

Do you have any chance to verify whether this works properly in a 
different operating system? It would require very specific handling 
violating the standard.

Thanks,

-- 
Jiri Kosina
SUSE Labs