Personal journal posts that originated elsewhere and were imported to DW don't show on reading pages. (It has to do with how the reading page is constructed -- if we let imported personal-journal posts show on a reading page, when someone did a first import, they'd be flooding their subscribers' reading pages with everything the import contained all at once.)

If you want your entries to show on both your LJ friends' friends pages and your DW subscribers' reading pages, the best thing to do is post them on DW and use the built-in DW crossposter to automatically crosspost to LJ. (That has the benefit that when you import your LJ again, the importer will put the LJ and DW versions of the comments on the same entry instead of you winding up with duplicates.)