Logitech S510 fails to send LeftCtrl+LeftShfit+.. key combinations

Logitech S510 support Looks broken at least in the Ubuntu distribution Ubuntu 7.10 - the Gutsy Gibbon, Also probably broken in one of the recent updates for the 7.06
I have a clean, up-to-date installation of Ubuntu 7.10

combinations
LeftCtrl+LeftShift+...
LeftCtrl+T
LeftCtrl+Y
do not produce any codes

I use LeftCtrl+LeftShift+LeftArrow and LeftCtrl+LeftShift+RightArrow to select a word in most text editors and Ctrl+T and Ctrl+Y are Firefox hot keys.

I am not using special multi media keys of S510. I tried only volume change on the right side of the keyboard and the key works

I used xkeycaps to test the keys. I tested all LeftCtrl+"letter" combinations. Only Ctrl+T and Ctrl+Y do not work. When i click LeftCtrl alone and LeftShift alone X recognizes the keys correctly. When I press LeftCtrl and LeftShift simultaneously only LeftCtrl is activated (yellow color on the displayed keyboard). LeftCtrl and RightShift work as expected. For example LeftCtrl+RightShift+Arrow Right selects a word on the right in gedit, etc.

Wired USB keyboard from HP (105 keys) works just fine for me - both Shifts and Ctrls operate as expected.

The keyboard itself is approximately two years old and works fine with WinXP. The desktop is mouse and keyboard only. I do not have media remote control.
Model name Y-RAK73
PID SC5340E
P/N 867612-0119

The S510 keyboard worked fine two weeks ago - just before an update of the 7.06 i did.

The problem is specific to the S510. Because of timing of the problem i suspect that the possible reason is the recent S510 related patch in the kernel (more details here http://bugzilla.kernel.org/show_bug.cgi?id=7352#c45 ). I will happy to collect logs. I can not recompile the kernel in my setup.