The opposite problem of sound breaking up or gapping is that the sound will be delayed and have a latency from the time an edit is made to the time you hear it.
For example, if you are playing back audio and change an envelope point. If it takes several seconds to hear the effect of the change, it means that you are experiencing latency.The solution to latency depends on the type of audio drivers you are using.
Reducing Latency Using Wave drivers
Go to the Wave preferences and reduce the number of buffers and/or size. Try different settings to try and find the right balance between performance and smooth non-gapping audio.
Reducing Latency Using ASIO
Go to the ASIO preferences and click the Open Mixer... button. Use your ASIO driver control to configure the latency. Usually, you will have some way to set the latency in terms of milliseconds. If possible, choose 10 milliseconds. 40-80 milliseconds is also tolerable. Always make sure that you have the latest drivers for your sound card. Visit your sound card manufacturer"s website to see if there is an update. If your sound card was an afterthought in your computer, you might look into getting a higher-end sound device. Many "integrated sound cards" have high latency.