Ever since Canopus and Artel agreed to support Boris within RexEdit, I have NOT 
been able to use Boris in RexEdit. With RexEdit versions prior to 2.03, it worked
 fine, but Natasha "went away" when I started on the 2.5x upgrade path. I tried a
 little bit of everything trying to get her back, with no success.

Since Boris worked everywhere else, I did NOT reinstall the Artel software, just the
 Rex stuff. Finally, as a last attempt, I *did* reinstall Boris 3.5. Still no Natasha.

But...

I then remembered the Boris 3.55 update, and installed it. During the install, I 
noticed that it ws looking for the fx-boris.vfx file----in the DVREX folder, NOT the 
MSP folder where it had resided (and worked from, for both RexEdit and MSP).

I copied the MSP version of fx-boris.vfx into the DVREX\vfx_plug folder (created 
during the 3.55 update), started RexEdit, and there she was, back in the 
Transitions list. Loads and works fine now.

Two new directories (folders) are created/needed with the update: vfx_plug and
 vft_plug. Both exist in the MSP folders, but need to be created in the DVREX folder.

Be sure, if you are using both MSP and Rex software, to run the MSP/Boris 
3.55 update, and then the RexEdit/Boris 3.55 update. You don't have to copy 
the fx-Boris.vfx file into the new folders in the DVREX folder before running the 
Rex/Boris update, but it doesn't cause any problems if you do.

Regardless of what you do, after the update is finished, copy the file from the
 MSP folders in to the DVREX folders, and all should work fine.

This applies to the Multi-platform version of Boris. I have the "bundled" 
multi-platform version from the Kitchen Sink at Videoguys. I don't know what 
will happen if you are using an NLE-specific version.

Also, this will NOT make Boris work in Premiere, unless you are already
 "authorized" in Premiere. If this is the case, you *may* be able to accomplish
 the same thing (BOris in RexEdit) using the premiere version of fx-boris.vfx.

Maybe a Boris/Premiere user can try this and report results to the forum??

glad she's back,
Mike Herberth
the Pancreative Group