In the Department of Chemistry and Biochemistry (where grommet is housed) it has become something of a tradition to give computers "dog" names (bigdog, smalldog, dogmatix, etc.). The Department has a good number of computers, so it has become difficult to find new names which honor famous "dogs". Grommet is named in honor of the British claymation dog, Gromit, of the television show Wallace and Gromit. For those who have not seen the show, Wallace is a human who lives with his faithful and scholarly canine companion, Gromit. From all appearances, Gromit is the more sensible and intelligent of the pair, and endeavors to keep his master out of trouble.
As for the misspelling of the name -- all we can say is check your sources, especially on the Internet! The system was named using the misspelled form "grommet" and went into productive use before the error was uncovered.