[xml] validation problem

["johnsag knology net" <johnsag knology net>]

Please bear with me I am new to libxml and xml.

We are moving a working c program that uses libxml from a Sun env to 
Cygwin.  The first compile and execute failed to return from a malloc call 
xmlCreateBuffer in tree.c.  From reading the news and some e-mails it was 
apparant that there was a malloc change in version 2.5.7. To fix this 
problems I decided upgrade to the latest version of libxml2 from 2.4.22 to 
the latest 2.6.7.

There were two validation errors that I recieved due to more validation 
checking in the latest version.  I fixed one but the other error that is 
produced does not actually seem to be an error.  It reports "Content model 
of "blah" is not determinist".

Question 1
Is it possible that a content model be determinist and through some error 
not be? and are validation error like warnings that or errors in that they 
stop further progress?

Question 2
My program continues after out this validation error and outputs Error: 
Failed to load external entity.  It seems from the e-mails I have read that 
is is related to a file reading problem with windows but I have not been 
able to fix it.  Is there something special that must be done to the file 
formats for windows?

Thanks