Posting issues I found:

gPodder takes a lot of CPU when downloading...
Also a "OMAP McSPI/0" process is taking up CPU when gPodder is running...

Why is that ?

Moreover when I enable the tray icon I get a second battery icon!
And that icon does not react to taps.

update: I think it was the speed of downloading.. it was downloading at 560Kb/s.
The next episode is going at 27Kb/sec and the tablet is much more responsive now...