[Zope] Odd ZCTextIndex behavior

Hi folks - I've noticed some odd behavior in the ZCTextIndex. I have an index of searchable terms that include, among other things, the author's employer's name. In instances where the company name is a string followed by a number (in this instance, "the451 group"), searching for the number ("451") even with wildcards ("*451*"), only finds references where the number is alone, and not part of any other string. Oddly, searching for "t*451" matches the name. I'm running the binary 2.6.2 (and 2.6.1) releases on linux. This occurrs in both. Any ideas why this would happen? Is this correctable? -jim