Toast 5 Wont Do 0 Secs, I'm sure it DID before Options

[Syne Wave]

I have been using TOAST for all my cd burning on my 733 G4, running this under 9.2 However for some strange reason it does not want to work when I choose 0 secs on a RW.
I am sure it did.
I have dumped prefs.
I went to the ROXIO web site and see that they offer an upgrade to make it work on using Buffer Underrun on CD RW's. So I tried again NOT selecting the use of BU - no difference.
All I get is that message which says the connection is unstable, which is shorthand for IT CANNT BURN.
Incidently, when I leave all the secs at 2 it works fine. Only I need that 0 as I have two tracks which run into each other. Aside from cheating and sticking those two tracks into one, I wondered if ANYONE in the Whole Wide World had a similar experience which they managed to fix