Thanks for hints. Icecat did not install, started but " not installed". Fennec installs , but does not start. Funny thing is that same networkpages workin nicely with JollaC and std browser , are not ok with tablet. So Full factory reset was the way I selected, we'll see the result.
Ok, now back on 4.0.1.48 , Icecat installs but not running , tries to open and dies. Fennec, also. I feel like there is an issue with x86 versions of the apk's since tablet is x86.