Smear problem with my new primer set - (Jun/06/2009 )

hi every one.....
i used to amplify my deisred fragement of 405bp (HCV) with my old primer sets (nested PCR) but after the stock has been exausted i syntesize new primer set from IDT (imperial) but i got only smear in my positive control samples then i again resynthesize same prime sequence from another company but the problem remains the same. i just got the smear in my sample with no specific, non specific band in my gel.
All the regents which i am using are same which gave earlier amplification.

Is your DNA degraded?

i have a similar problem... if u were able to fix this, please share how!!! thx!