In addition to a standard size buffer setting, Digital Performer also has an additional setting called "Work Priority". The default value for this setting is 'High'. If you would like to use a buffer size of 1024 with your Liquid Mix, you may need to set the Work Priority setting to 'Low' or 'Medium'. Otherwise, you could experience in-continuity in audio streaming.
The buffer settings for Digital Performer are accessed in "Setup > Configure Audio System > Configure Hardware Driver..." as shown in Figure 1 below.