DNA-dependent activity of RT?

[Simone Marker]

Hi,

does anyone know if reverse transcriptases normally used for RT-PCR have a 
DNA-dependent DNA-Polymerase activity beside the RNA-dependent 
DNA-synthesis? I use MMulV H- from finnzymes or cMaster from Eppendorf. My 
RNA samples are acceptable free of genomic DNA (according to the noRT 
control template) but nevertheless I wondered if my RT-PCR products really 
originate from only reverse transcribed RNA and not from residual small 
amounts of "RT-amplified" genomic DNA...
I know that there is a DNA-dependent RT activity in the reverse 
transcriptases of some viruses, but I don't know if I have to take that into 
consideration with commercial RT.

I appreciate every comment.
Thank you