Error using Nero API from Dll

I am using the Nero Api sdk 1.03, with Nero version 6.0

I have VB code which calls a c++ dll which calls the Nero Api.
The CD is bruned correctly but the NeroBurn function exits with an exception, after the log line of burn process completed successfully.

Did anyone get an error like that?
Any ideas of where it might be coming from, or what type of exception i should catch.