On some of my older DVDs, there is some kind of odd trace around the edge of the disc... you can see it in the image where the light is reflected. I can wipe it off, but it's really sticky and takes some time to clean up. More sticky residue is all over the disc, so the trace only seems to be some accumulation of stuff that's all over the bottom side. Best thing that worked so far was soap and water and a bit of patience. Any idea what this is and how to prevent this for my other discs? Or is it a known issue for some weird kind of disc? Discs obviously don't work until they are cleaned.
Were either of those DVD sets pressed by Warner Brothers? Apparently the star trek TOS DVD's were done by them around 2007, so it could be possible DS9 and TNG could have been as well.
I ask since almost all Warner Brothers DVD's made between 2006 and 2009 were defective, and extremely prone to disc rot.
Edit: though oddly no star trek titles are on this list of affected titles.
You can compare your discs to known affected discs using this guide.