If you installed InDesign AFTER you installed SDLX, you need to uninstall and reinstall SDLX again, so the proper plug-in is copied onto the InDesign folder.
InDesign Filter Options Dialog Box
SDLX 2007 has filters for both InDesign CS and InDesign CS2. However, an InDesign filter is only installed if the InDesign application is already present on your computer when you install SDLX. Only the filter appropriate to the version of InDesign on your computer is installed. This means that:
* If you install InDesign after installing SDLX, you have to uninstall and then reinstall SDLX to get the InDesign filter.
* If you have the SDLX filter for InDesign CS installed and then upgrade to InDesign CS2, you have to uninstall and then reinstall SDLX to get the InDesign CS2 filter.
The SDLX InDesign filter installs a plug-in into the InDesign installation folder.
It's on the SDLX Projects User and Administrator Guide