Hi Everybody.
After almost a week of gogleing and lurking in this forum (specially in the FEC thread, of +200 pages), im about to throw in the towel.
Im working in a Zencart (v1.5.3) that uses Fast Easy Checkout (1.15.3)

The site owner wants to use the onepage checkout feature of the FEC (shipping+payment in the same page).
As you must know, FEC redirects checkout_shipping to just checkout, a single page with both features (shipping + payment).

In the other hand, the previous developer installed a mobile zencart template.
The mobile cart template uses the checkout in stages (first shipping, then checkout).

The problem i have is that seems that the redirection rule used by FEC is affecting the mobile version, then, when i go to checkout using mobile, instead of going to checkout_shipping, i end being redirected from, per example: site.com/index.php?main_page=shopping_cart&zenid=sttlirsledb05gq5c35irebjv1 to site.com/index.php?main_page=checkout&fecaction=null&zenid=sttlirsledb05gq5c35irebjv1
instead of site.com/index.php?main_page=checkout_shipping&zenid=sttlirsledb05gq5c35irebjv1


I think that its clear that the FEC is involved since you can see the adding of "fecaction=null" in the url.

I spent DAYS going back and forth, trying to find the script where the redirection happens, and in which context.

Maybe its more easy than i think, but to be honest, im very confused now. I just need that the redirection rule of FEC dont be applied to the mobile site.

If anyone can illuminate me, really, thanks in advance.

Best regards.
Norberto