Can't replace blocks... how come?

[Souldier77]

I used to be able to easily replace blocks while comparing text files by clicking arrows in the center column.
But there are no arrows anymore. And CTRL-F9 does nothing. That functionality has suddenly stopped and I don't know why.

I'm running ExamDiff Pro 6.0 on both a Windows 7 and a Windows XP machine. Neither one will successfully let me replace blocks or even edit the text manually on either file being compared.

Can you help?

See image: https://docs.google.com/file/d/0B1Dkpm7 ... nFwWDhRNjQ

[psguru]

Please see http://www.prestosoft.com/edp_faq.asp#3