The Arista kit is not developer replenisher. That may make the difference.
The paper does not go down in contrast with age in my experience. I have made prints on Supra III that was 10 years old, and the only difference was about 20 red to correct for the cyan speed loss.
PE
I forgot to mention that the film I used was refrigerated since I bought it, and expired in 2002. I noticed a slight amount of base fog in the negatives, which could be due to age or the somewhat unorthodox way I processed the film. I had bought a Unicolor dry powder C-41 kit from Freestyle, and was searching this forum for tips before mixing it up. I found your posts about the poor performance of C-41 blix, and started looking for an alternative with chems I had on hand, as I didn't want to order and wait for more chems to arrive at the time. Here's what I ended up with:
1. Develop with developer from Unicolor kit, 3:15
2. PE's clearing stop bath with Acetic Acid and Sodium Sulfite, 2:00
3. Rinse, 2:00
4. Bleach with Ferricyanide/Bromide bleach, 6:30
5. Rinse, 2:00
6. Fix with Arista Premium Oderless Fixer, with 1/4 tsp Sodium Hydroxide added to raise PH to between 6 and 7, with universal PH test strips. 4:00
7. Rinse in several changes of water, 10:00
8. Stabilize
I guess I should be lucky I got any images at all with all the improvising I did. I plan to buy real C-41 fix in the future.