ok i finally found a fix to the issue i had where a poser mat pz2 wasn't apply to the outfit piece.  I've had this happen to me twice - once on a texture addon for an outfit, and once for a full skin mat for a character.

I hope this shows up properly in the message here - if it doesn't, or if I have confused you, pm me and I can whip up a pdf and email it to you.

• Open up the .pz2 file in a text editor - Editpad Lite or Notepad++ are good, I don't use the Notepad that comes with your OS.

• At the top, you should see something like this:

{

version
    {
    number 4.01    }
figure    {
    material sole

(this is for a pair of shoes, hence the "material sole" - the sole will change depending on what the mat is for)

• It SHOULD read:

{

version
    {
    number 6    
    }
figure    
    {
    material sole

Note how the formatting was changed - an extra line was added before that } after the number 6.

Save the .pz2 file to the same place as it is (obviously).

That SHOULD make it apply now.

(oh, i change the number 4 to number 6 as I believe the number 4 can cause issues in later issues of Poser....something like that. I don't use poser but that's been ingrained in me so I just do it automatically now, I don't know if it affects DS)

That's just one possible reason why a .pz2 mat may not apply automatically in DS. It's not a fix for every reason - as I don't know ALL the reasons a mat would not apply. :D