Altiris 7.1 installed agent inventory problem

Hi all,

i found that there is a problem when I search the installed agent.

 

for example, when I search Asset#1234 in the morning, I can find it from Altiris. However, when I search Asset#4567 at the same time, I cannot find the record in it. Afterward, when I search Asset#1234 in the afternoon, I cannot find the record anymore. But, Asset#4567 is shown in the Altiris suddenly.