This normally indicates that the program is in the process of performing the last requested action. Typically, if you give it time, the program will start responding again. The amount of time that you have to wait depends on the amount of resources that are available for PhotoImpact Pro.
Here are some suggestions on how to minimize this issue in the future:
Turn off all unnecessary programs. If you have other programs running at the same time, they will take up system resources that PhotoImpact could be using.
Minimize the number of open images. For each image that you have open, the usage of the system resources will increase. If you can, close out of any unnecessary images.
Install more RAM. Generally speaking, having more RAM installed will help the performance of all programs on your computer.