Upgraded from 3.4.2 to 3.4.3 final (from libreoffice.org website). Spell checker completely disappeared, to the point that "Available Language Modules" under Language Aids is completely blank, with no options present whatsoever. Did not have this issue in 3.4.2.
Uninstalled/cleaned out registry, then re-installed fresh version of 3.4.3 and spell checker is still MIA.
*** This bug has been marked as a duplicate of bug 37195 ***