[NTG-context] Combining two pages on one, in landscape mode

Dear list members, the following command: texexec --pdfcombine \ --combination=2*1 \ --paperformat=landscape \ --nobanner \ --result=twoinone.pdf \ file1.pdf file2.pdf used to work to get file1.pdf and file2.pdf in twoinone.pdf with two pages at one, and in landscape mode. However, since installing ConTeXt 20070403 (the minimal version), this no longer works for me. I get the output "texexec: No match." I also get the same error with the ConTeXt coming with texlive on ubuntu feisty. Any ideas of how to solve this? Thanks in advance /Micke P