I am not sure if this an interface bug or a resource bug -- perhaps a combination.
I have noticed that a number of times that when I try to select text clicking and dragging the mouse, no text is marked in blue as selected. But if I press Ctrl+K to highlight the text after dragging the mouse over it, it is highlighted with my recent highlighting pen. So even though the text does not display as selected, it is actually selected. This text also shows as the selected text in the context menu.
An example is Grant Osborne's Revelation commentary in the Baker Exegetical Commentary on the New Testament on page 417. Some of the text will display as selected, but other parts of this page do not. For example, if I try to highlight "If the beast in 11:7 and 13:1 (see also that passage) is an individual rather than just a symbol for the evil empire, so the witnesses are also probably individuals who will appear at the end of history", the text does not appear as selected. But I can select text earlier in the same paragraph.
The odd thing is that if I get a running start and begin my selection earlier on the page, I can select text through this portion of the page as well. It seems to matter the starting point for the highlighting.
Sometimes, when I drag the mouse over the text with the left button clicked I get a circle with a diagonal bar through it as my mouse pointer. This is particularly true in the quotation I noted above.
