(1) Actually, they are important... The nature of the defect does give rise to whether you can demur or not, and if you cannot, then a demurrer is out of the question and you're only dealing with the uphill battle of a change of venue.
(2) I'm not getting the part about it being a "substantial defect" and yet it is just a "typographical error"... Typos can be easily corrected and have very little impact, if any, on your ability to defend yourself as compared to a substantial error which may require the citation to be reissued/refiled.
So why don't you share with us what the error is?

