Here is a DEMO
Make sure the checkboxes are not inside an anchor tag. You can apply data-role="none" to stop jQM from styling the checkboxes:
<ul id="components" data-role="listview">
<li>
<label>
<input name="checkbox-0" id="checkbox-0" type="checkbox" data-role="none" />Some random text #1</label>
</li>
<li>
<label>
<input type="checkbox" name="checkbox-0" data-inline="true" data-role="none" />Some random text #2</label>
</li>
</ul>
A second option is a vertical controlgroup:
<fieldset data-role="controlgroup">
<legend>Vertical:</legend>
<input type="checkbox" name="checkbox-v-2a" id="checkbox-v-2a" />
<label for="checkbox-v-2a">One</label>
<input type="checkbox" name="checkbox-v-2b" id="checkbox-v-2b" />
<label for="checkbox-v-2b">Two</label>
<input type="checkbox" name="checkbox-v-2c" id="checkbox-v-2c" />
<label for="checkbox-v-2c">Three</label>
</fieldset>