Pdflatex isn't in the Export->Custom dialog. The following patches fix this (pdflatex has to be added manually, like latex, cf. Exporter.cpp).
Jürgen
Index: src/frontends/controllers/ControlSendto.cpp =================================================================== --- src/frontends/controllers/ControlSendto.cpp (Revision 22326) +++ src/frontends/controllers/ControlSendto.cpp (Arbeitskopie) @@ -63,8 +63,10 @@ Buffer const & buffer = kernel().buffer(); - if (buffer.isLatex()) + if (buffer.isLatex()) { exports.push_back("latex"); + exports.push_back("pdflatex"); + } else if (buffer.isDocBook()) exports.push_back("docbook"); else if (buffer.isLiterate())
Index: src/frontends/qt4/GuiSendto.cpp =================================================================== --- src/frontends/qt4/GuiSendto.cpp (Revision 22335) +++ src/frontends/qt4/GuiSendto.cpp (Arbeitskopie) @@ -149,8 +149,10 @@ exports.push_back("lyx"); exports.push_back("text"); - if (buffer().isLatex()) + if (buffer().isLatex()) { exports.push_back("latex"); + exports.push_back("pdflatex"); + } else if (buffer().isDocBook()) exports.push_back("docbook"); else if (buffer().isLiterate())