Show[
Graphics@
Text[Style["12345678901234567890123456789012345678901234567890", Medium,
Bold], {2, 0}],
Graphics[{Thick, Red, Line[{{0, 0}, {1, 0}}]}],
Frame -> True
]
The edge of the frame that is drawn goes through approximately the middle of the long text, and does not include the right end of the text. Seems like Mathematica looks at the midpoint of the text and doesn't try to include the whole text in the frame.
This is Mathematica 8 running on Windows 7.
Attachments: