PVS-Studio warning V547 for Ultimate ToolBox

void COXCoolComboBox::MeasureItem(....)
{
  if(lpms->itemID<0)
    lpms->itemHeight=m_nDefaultFontHeight+1;
  else
    lpms->itemHeight=
      m_nDefaultFontHeightSansLeading+1;
}

This suspicious code was found in Ultimate ToolBox project by PVS-Studio static code analyzer.
Warning message is:
V547 Expression 'lpms -> itemID < 0' is always false. Unsigned type value is never < 0. UT oxcoolcombobox.cpp 476

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/