From what I understand, every time Gwibber refreshes, it makes two requests - one for your main timeline, and one for your replies timeline. If you have it set to 2 minutes, you're already making 60 requests in an hour (the limit for non-whitelisted accounts is 100). It shouldn't be locking you out after 20 minutes though. I suspect this is a separate issue, so perhaps start a new ticket about it?
From what I understand, every time Gwibber refreshes, it makes two requests - one for your main timeline, and one for your replies timeline. If you have it set to 2 minutes, you're already making 60 requests in an hour (the limit for non-whitelisted accounts is 100). It shouldn't be locking you out after 20 minutes though. I suspect this is a separate issue, so perhaps start a new ticket about it?