It seems to be a similar problem as the one described in Eclipse cut/copy/paste not working. However, the problem does not seem to be related to CodePro AnalytiX plugin.
At some point after process of debugging, copy&paste and delete keys do not work. Also from Edit menu these options are hidden.
After restart of Eclipse everything works fine again.
System : Windows 7 Enterprise, SP1
Eclipse Juno Service Release 2, updated.
A hint given in Eclipse Forum, e.g. remove key bindings in Eclipse, does not seem to be a solution because it just removes these shortcuts.