PCR troubleshooting - (Dec/17/2008 )

I have tried some methods,touchdown,touchup,different concentration primers or genome templates,different company`s PCRmix,even hifi pfu polymerase,DMSO,MgCl2,glycerol. I get only no result or smear band from the well to the middle of the lane(750bp) ,where my expected band should be.
I suspect that my target sequence can form template-dimers.That is to say my target sequence each other can form dimers in some regions.
How can I check or prevent this condition?

I gave up the primer sets and ordered new sets.
Thank everyone.
You are warm-hearted persons.

Try PCRboost. Its from Biomatrica. I use it religiously. It has really helped me with my hard to amplify samples.

Austin