Can anyone here help me to reconclie the differences between these two statements, made 3yrs apart?

From the '07 MD&A on Sedar:

Any sample
giving detection limit or less than approximately 250ppb can be considered waste and further treatment,
except under special circumstances, is not warranted.

And from yesterday's news release:

Consequently, for exploration purposes, quartz-bearing
zones that show values greater than approximately 100ppb are considered mineralized
and warrant further attention.

Does this mean that what they considered waste 3yrs ago is now considered mineralized?

Or is this explained by the different sampling methods described?

Any help would be appreciated.