I've got the same stick. I've used it under a great variety of circumstances without ever observing the problem you report. On Windows XP, I sometimes use the Logitech Wingman Profiler software and sometimes I don't. Under Linux, I never use the Logitech software. I've always mapped the text buffer toggle control to a keyboard button using AH control mapping. Never had a problem with that or "Check 6", under XP, Vista, or PcLinuxOS, with or without Logitech software under XP.
-Peabody-