I started noticing a microB browser 'non-connecting' problem a while
ago, and it seems to be getting more frequent (maybe due to
something installed?).

Starting from the bookmark page, if I fill in the search box,
or hit the Google box directly, I'm shown a blank page with "Web"
at top and my entry (or Google's address) at bottom, but sometimes,
there's no moving-blue-bar (or it appears only for a moment), and
nothing else happens.
If I then poke the search box and hit Enter, or "Reload" the page
from the top menu, "Web" is replaced with "(untitled)", and again
nothing else happens.

Also, if I attempt to open a link from a locally-saved
file, again, sometimes nothing happens, even if the link displays
as a full HTTP web address (as opposed to a usually non-existent
"file://localhost..." address).

Apparently, for some reason microB isn't attempting to connect to the
(cellular) network. Note that when this happens, the Opera browser
still works normally.

And, as far as I know, the only reliable remedy for this is to reboot
the n900.
Turning the datalink or the cellphone-link off and back on
again, or closing and re-opening the browser, usually doesn't work
(rarely it does, but I haven't figured out the exact procedure yet).

Any idea what's happening?