Cumbria Family History Society

I have been using the Monumental Inscriptions for Stapleton and Bewecastle and have found them to be an invaluable resource for putting families together.  I have also found several situations where the inscriiption does not match the burial record in the Parish Registers.  For example the tombstone of my 5x great grandfather James Routledge (1750-1826) (C49) includes the burial of his father William's first wife, Esther (C49 reverse).  The inscription says she died 7 May 1737 but the Stapleton Parish Registers give a burial date of 8 July 1740.  I have searched the PRs between 1737 and 1740 and no other burial for "Esther, wife of William Routledge" appears.  Similarly the inscription for Jame's mother Jane (C49 reverse) gives a death date of 6 April 1760 but the Stapleton PRs record that "Jane, the wife of William Routledge" was buried 21 March 1760 and I find no burial for Jane Routledge in April 1760.  It may be that James first erected the headstone for his infant daughter Mary who died in 1784 (C49 reverse), 40 years after the death of Esther and 24 years after that of his mother Jane  and he was misaken on the death dates of his father's two wives. 
Has anyone else noticed such descrepencies?
Is the burial record a better source than the monument? 
By the way thank you, thank you to the authors of these transcriptions!!

Jean, remember that the headstone probably gives the date of death, but the PR is the Burial date not the date of death, they are not the same though normally it is within a few days and the PR may also give the date of death. The examples you give are unusual, particularly being buried before you died. There can of course be many reasons for errors, headstones can be erected many years after the event and wrong dates put on them, wrong dates can be put in the PR's and there can be transcription errors in both the PR's and MI's.
I have come across cases where people have been re-buried at a church several years after they died as they were originally buried at a different church but later moved 'home'. Burials several weeks after death may also not be unusual if the person died away from home and had to be transported back prior to the days of the railway.
I don't think you can give a definitive answer that one record is better than the other and like a lot of genealogy you have to make the best interpretation of the facts that you can. It can be worth going back to the original PR's just to make sure there are no transcription errors and if the stones are still there checking them to be sure they were not misread. sometimes there are photos on Billion Graves or other websites.