Are you guys using two hand ascenders on your described SRT method?
It looks like you are describing a single hand (left) Ascender and a pulley tied below it similar to the RAD/Yo-yo system posted on the New Tribe Web site. (Tengu Tips Area).

I used to have the same problems in the SRT switch over until Peter told me what I was doing wrong and now it is so natural that I can do it without any stress or extra gear. ( I use the Gri-gri instead of a figure-8 for descending). I have two ( Left and Right CMI Ultracender) Ascenders that are used for SRT without any pulleys involved.
I gave up using the Fig-8 because it does not lock up like the Gri-gri and because it twists the rope too much with every descend.