Right now, restoring visibility of dropdown controls does not work in IE6.
In function restoreTab, please change
this._saveDesableSelect[k].tag.style.visibility = this._saveDesableSelect[k].visib;
to
this._saveDesableSelect[k].style.visibility = this._saveDesableSelect[k].visib;
Comments: Workaround found, see comments.
In function restoreTab, please change
this._saveDesableSelect[k].tag.style.visibility = this._saveDesableSelect[k].visib;
to
this._saveDesableSelect[k].style.visibility = this._saveDesableSelect[k].visib;
Comments: Workaround found, see comments.