Transfection of L929 cells with Poly (IC) - (Jan/11/2008 )

I am having two issues with my transfections!
1) I am having a really hard time transfecting L929 cells with a GFP construct. I have this reagent called GenJet and i managed to get something like 20% transfection efficiency (much much better than fugene6) after 48hrs post transfection. However, i need to check a protein's localization pre and after stimulation and 20% efficiency is in the low side. Is there a better way/reagent to increase uptake of DNA in L929 cells.
2) I am trying to transfect these cells with poly (IC). Currently I am adding it directly in the media at the concentration of 10 micrograms/ml and i usually harvest them 6 to 9hrs post addition. Is that a good way is there a better way? does anyone have a decent protocol for this? I am at my wits end with this situation!
thanks