Originally Posted by Guessed

A bookmark can enclose a text range or it can be 'collapsed' in that its end is in the same position as its start. This is the equivalent as having a selection or just a cursor position.

So oBM.Range.Text will only show content if the range's end is greater than its start. You can either modify the contents of the bookmark's range or use the earlier suggestions as more bulletproof methods of avoiding this problem.