Keywords with periods around them

Dear Google, I searched for the keyword 54286614780461303 and got no results. However, the page http://www.mersenneforum.org/showthread.php?t=1544 does contain the keyword. This page is in your archive (I found it by other keywords). The problem seems to be because the keyword is embedded within a string "blah.54286614780461303.blah". My suggestion is that you treat periods as word separators. (You can still also continue to index the longer string with periods embedded.)