Minor annoyance - invisible cursor with PDF

Sorry, this is not a great question, but it bugs me. When opening a PDF document sometimes the cursor becomes invisible. Has anyone else seen this? I have upgraded my version of the PDF reader and it still occurs.

Windows XP, although I believe it occured unders Windows 98SE as well.

Oh, and as an aside, why do people apologize for linking to a PDF file? Download the reader and get a lot more documents than you could otherwise. What’s the beef?