This line will result in `NaN` in IE7-8, which _do_ support `obj.getBoundingClientRect()` but _not_ `window.pageXOffset` (`undefined`), ergo, e.g. `4 + undefined - 3` &rarr; `NaN`).  Additionally, the `docType` value (or lack thereof) can also affect which property to query for the value (ugh!). :-1:

I believe the corrected version would be as follows:
```js
var pageXOffset = window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft || 0;
info.left = rect.left + pageXOffset - document.documentElement.clientLeft;
```