I have had Saison yeast stop for a week, then start back up like nothing had happened. My 1.054 Saisons get down to 1.002-1.004 range. Temperature control is very important for these yeast, and they like to be warm, as in 80+F warn.
I have seen this as well, though not for quite some time. Interestingly enough, contrary to most other posts about Saison strains, I have no issues whatsoever with my fermentations. They have become quite routone normally being finished in 1-2 weeks depending on gravity. One thing that has helped me is very steady temp control I use a thermowell and a heat wrap. I start fermentation off in the mid to high 60s, let it chug along in the high 60s for 2 days or so and then slowly ramp it up to the high 70s over the next 3-4 days then hold there until complete. Usually done in 1 week.
But, the interesting thing about this thread is that the OP doesn't sound like he is witnessing fermentation. He said he doesn't even see airlock bubbles. Just a few bubbles on the surface. I have seen this in lots of beers, especially once that have sat in the primary for more than 2 weeks. Having witnessed this several times I have often wondered if this wasn;t simply caused by the yeast breaking down. But, like I said earlier, hard to tell what is going on without a hydro reading.