Re: 23.98fps FCP7 roundtrip?

I just had the same issue, for a short film, my fix (that worked very well and stayed in sync) is:

I duplicated the media managed folder (with all the final film media in it)
opened cinema tools, conformed all of the 23.98fps to 24fps
Created a new project in FCP 7
Copied the final timeline to the new project
copy all tracks of the old timeline and paste it on a new time line that I created as 24 fps (i made sure that it is 24 and not 23.98)
Checked that its all in sync (it was)
created the xml and imported it to resolve, made sure that resolve timeline is on 24fps and the video monitoring was on 24p (not PsF) , imported the sound from the FCP 24 timeline and all was in sync.

Hope it can work for you as all of my previous test in resolve did not yield any good results, I even tried to change the XML but to no avail.

Yoav Dagan
Colourist / Onliner
TiNT Post Production
South Africa
tintpost.com