There was a small bug in the One-Click Postage 2.8 REV B, which can cause the text “Send!” (and a picture) to appear on the end of the asks you answer.

I’m terribly sorry about that, and it has been fixed now. To update it:

1. Click on the X icon
2. Click Manage Extensions > One-Click Postage 2
3. Click on Re-install / Manually Update this Extension

Again, I’m really sorry about that.