inconsistent validation results

Hi,

i have been validating a number of pages for accessibilty testing. At one
point i accidentally validated the same page twice (by direct file upload)
not a serious problem except that i noticed that i got a different number of
errors on the two reports (93 the first time then 102) despite the fact that
i used exactly the same file, in fact repeatedly validating the same page
continues to give a different number of errors though i do at least get one
or the other number every time. I note that the source shown in "Below is
the source input I used for this validation:" differs between the two
reports. Since then i have re-validated all the pages which previously
passed validation and am now finding that every page is reporting a large
number of errors related to non-closure of meta tags. When previously
validated the source in "Below is the source input I used for this
validation:" shows no unclosed tags, the actual source does in fact have a
number of unclosed tags. I'm extremely concerned at this inconsistency as it
suggests that the validator is not validating the exact source as uploaded
and in fact cannot be relied upon without making a line by line comparison
of the source input used for validation and the actual source. At this point
i'm unable to provide the exact source used due to client confidentiality
but may be able to do so if necessary. I have not previously noted any
serious inconsistencies except between different validation methods (e.g.
file upload versus validate by URL or cut and paste) but of course i do not
usually validate a page more than once. I'm sending this email prior to
submitting a bug report via bugzilla please can you assist.

Regards,

Julian Abbs