Impossible to find a result if the string entered is not at the begining of a word

Impossible to find a result if the string entered is not at the begining of a word (at least if the string is in the page name - didn't tested all the cases)

For example :
If I search for the SonySR35 and if I type : SonySR35 : I'll get the right result
If I type Sony : I'll get results, all the Sony results
If I type SR35 : I won't have any result

Had this on a 1.1.1 XEM (1.3.2 XE) - don't know the Lucene Plugin version corresponding.