google takes a while to refresh, and you cant force it manually... does it work now?

No. Manual refresh doesn't work at all; but if I remove the calendar and re-add it, it works fine. Maybe a problem with smart lists?

no, I explained myself badly.

What I meant is this: you add tasks in RTM. You can see them there instantly. You have Gcalendar "reading" them, but it "reads" when it wants (usually in 3 hours tops), hitting refresh doesnt tell him "read again". (There is no way to tell him read again, this is a common complaint).

Adding a new feed however forces a re-read (because it believes it's brand new and has to sync all again!)

So after a while, it should read them alone and it should work. If you are in a hury to see them, re-suscribing is the best way.
Also, 30Boxes has a button to "read again", try it if you like.

Thank you

Seems like Google is reading the webcal feeds more often now. At least once a day. Before it seemed to take days if not weeks.

In my experience it takes less than that (around 3 hours as I've said).
Not having a "reread" button is probably my top complaint for Gcal... and the main reason why I've not decided to dump 30boxes yet.