There's a global property called patientSearch.matchMode which affects how patient names are matched. Can you add it to the properties created during install? It seems to be part of core OpenMRS, but I had to add it manually.
This is not only for convenience, but to make users aware the feature exists. I concluded, wrongly and grumpily, that OpenMRS search wasn't very flexible. I stumbled over the property in the documentation when I was looking up details for the other search properties.
Here are the details from http://wiki.openmrs.org/display/docs/Global+Properties+Descriptions:
"patientSearch.matchMode 'anywhere' means that a search for 'lis' will hit on both 'lisa' and 'dalis'.Valid values: ANYWHERE, START Default value: 'start', meaning that patient name searches are matched at the beginning of names"