Thank you so much for your reply– that was the issue.
For those also experiencing this, please note the following stop words in Lucene Analyzer – these will be removed during tokenization:
"a", "an", "and", "are", "as", "at", "be", "but", "by","for", "if", "in", "into", "is", "it", "no", "not", "of", "on", "or", "s", "such", "t", "that", "the", "their", "then", "there", "these","they", "this", "to", "was", "will", "with"
Please note that "s" and "t" are no longer stop words in Lucene 2.2; however Alfresco 2.1-3.1 use Lucene 2.1.
(Stop words extracted from org.apache.lucene.analysis.StopAnalyzer used by org.alfresco.repo.search.impl.lucene.analysis.AlfrescoStandardAnalyser)