find sudstring on text (data type) field failure

I was trying to find a substring on a text (data type) column like 'cat foo dog ...'. <br />I use the query below<br
/>SELECTid FROM table WHERE name LIKE '% foo %';<br />Sometimes the query return with nTuples=0 but there are matching
rows.<br/> On retry, the query return with expected results. Any ideas;<br /><br />(postgres ver 9.2, libpq - C
Library)<br/>