I have noticed that a getter in my view model is called multiple times causing me real trouble as this getter executes database transactions. The reason for this is that the control (in my case a selectbox) has been declared inside a Grid to make a nice form layout:

<row>Type
<selectbox model="@load(vm.questionnaires)">
<template name="model" var="q" >
<label value="@load(q.name)" />
</template>
</selectbox>
</row>

In this case the getQuestionnaires() is called four times.
If i declare the <selectbox> outside the grid then it is called only once.