I noticed today trying to mixdown a ReWire project with Reason 7 results in the first 1.2 seconds of the ReWire audio to go missing. Everything else seems OK. Output wav file is short, missing about 52800 sample (44.1) at the front of the file.
Tested and reproducible on MacBookPro OSX 10.9.1 Nuendo 6.0.6 and Reason 7.0. Have not yet tried on Studio PC which is running Win7.
To reproduce, set a Reason project starting with notes in the first bar. Audio Mixdown ReWire R+L with no other Nuendo channels and no plug-ins. 16/44.1/wav for my test.
Anyone else run into this? Saw no other post. Have not tried moving reason to start on a latter bar. Regardless ReWire is not working correctly with mixdown.