I think you were actually pressing and holding over a link. On a normal link (in 2.2.1), if you press and hold on a link, the url will come up as a the bubble you mentioned. So im guessing the link you were pressing is not a proper link, it may be a HTML A tag with an onclick event or something). In 3.0, when you press and hold a link, a menu will come up instead.
I used to notice the same thing before I went to 3.0 . I had no idea what action meant and it just went away when you released your finger. It's nothing to worry about, you can't click on it or anything so I have no idea why it even showed up. Doesn't happen in 3.0.