Can't click mouse below last paragraph to insert cursor

[WaltR]

I'm having kind of a weird problem in Word 2007, I'll try to explain.

I do a lot of copying from PDFs to create new Word documents. Sometimes after pasting text into Word, I can just put the mouse pointer a couple of spaces down from the last paragraph and click, setting up for the next paragraph to be pasted. But other times I have to put the cursor at the end of the last sentence and enter twice, mouse clicking won't work. Anyone know what might be causing this and if there's a way to get control over it. It's a lot easier to just click the mouse once. Thanks.