I cannot reproduce this problem (I was moving the cursor innocently through nested descriptions in read-only file TOC.lyx) but nevertheless you might consider it interesting.
==18947== Conditional jump or move depends on uninitialised value(s)
==18947== at 0x816C72E: LyXText::setCursor(LyXCursor&, std::_List_iterator<Paragraph, Paragraph&, Paragraph*>, int, bool) (text2.C:1363)
==18947== by 0x8170055: LyXText::cursorPrevious() (text3.C:284)
==18947== by 0x81719B6: LyXText::dispatch(FuncRequest const&) (text3.C:658)
==18947== by 0x806A928: BufferView::Pimpl::dispatch(FuncRequest const&) (BufferView_pimpl.C:1323)
==18947== by 0x806244A: BufferView::dispatch(FuncRequest const&) (BufferView.C:255)
==18947== by 0x81151AF: LyXFunc::dispatch(FuncRequest const&, bool) (lyxfunc.C:1622)
==18947== by 0x81113EE: LyXFunc::dispatch(int, bool) (lyxfunc.C:806)
==18947== by 0x810FA89: LyXFunc::processKeySym(boost::shared_ptr<LyXKeySym>, key_modifier::state) (lyxfunc.C:253)
==18947== by 0x8067950: BufferView::Pimpl::workAreaKeyPress(boost::shared_ptr<LyXKeySym>, key_modifier::state) (BufferView_pimpl.C:562)
==18947== by 0x8072514: boost::_mfi::mf2<void, BufferView::Pimpl, boost::shared_ptr<LyXKeySym>, key_modifier::state>::operator()(BufferView::Pimpl*, boost::shared_ptr<LyXKeySym>, key_modifier::state) const (../boost/boost/bind/mem_fn_template.hpp:213)
text2.C:1363 is: // None of these should happen, but we're scaredy-cats ==> if (pos > pit->size()) {
Regards, Michael