If you experience such issues while running ACT! it does not mean that ACT! Database is broken or works improperly. The issue is that you do not have enough RAM. If you use a PC with a little amount of memory, 4 GB, for example and run different applications, it will use most of its time to calculate and move memory from the memory to the hard disk and back (swapping). As ACT! is a database, there might occur issues with swapping. You can read about this in more details in this article. This way having several different processes and ACT! database running concurrently will do no good if you have a PC with 4 or 8 GB of memory.
You may check your Task Manager for memory consume:
When having 16 GB memory or higher you will not experience such type of issues and your ACT! will run smoothly.<