The Pronunciation of です and でした

I do find it interesting that all of the Japanese language learning books sing the praises that 'what you see is what you get' with regard to Japanese pronunciation and ひりがん but I have discovered two major exceptions in my current studies.

です = 'des' not 'desu'
でした = 'deshta' not 'deshita'

Of course, if you look at the mess surrounding the English verb 'to be,' I guess a little pronunciation weirdness isn't too tragic in the scheme of things.

All's fair in love and war and language learning!

~Happy, Happy Japanese Learning to You!~