Around 2012, the individual seasons of Seinfeld were repackaged in slim cases (instead of the much bulkier cardboard cases).

However, Season 4 seems not to have been repackaged in the repackaged slim case. I've seen some posts online of people saying that they could never find Season 4 in the repackaged slim case.

Also, on Amazon and Best Buy's websites, the other seasons are listed with a 2012 release date, but Season 4 still has a 2005 release date.

Does anyone know what the deal was with Season 4?

I noticed that too.

The same thing happened with Magnum P.I. For quite some time, all eight seasons, except for season 3, had been reissued in smaller packaging. Eventually, season 3 was reissued in smaller packaging.

I have no idea why this happened for either show. Perhaps the holdout season for both shows had more copies of the old version sitting in a warehouse, and they were waiting to sell those before the reissue came out.

I have been wondering the same thing. I much prefer the standard dvd packaging of the re-released sets.

This would be my guess. Perhaps season 4 of Seinfeld, and season 3 of Magnum are where the studio saw a decline in sales such that the subsequent season for each was produced in less quantity.

That would be an unfortunate irony for Seinfeld, as season 4 is, perhaps, its greatest season.

As mentioned, the missing Magnum season just recently was re-released (literally within the last couple weeks) and really not terribly later than the other seasons.

Exactly, so I'm not necessarily thinking that. Although I can't think of another reason. I could have sworn I saw Season 4 in slim packaging at Best Buy last Christmas but maybe not.

When Family Guy was reissued the first volume was the last one to get released and its easily the best of the series.

It makes sense that Season 4 is where the sales took a dive. Season 4 was basically the 2nd release since they released the first three seasons/first two volumes simultaneously.