Hi Leonid,
SQL Anywhere 16 fixed the problem of the INSERT ON EXISTING UPDATE statement by build 2119.
============(Build #2119 - Engineering Case #782421)============
The server did not return an error if an INSERT ON EXISTING UPDATE statement
violated unique indexes on the insert table and silently deleted violating
rows. This has been fixed.
2246503 - SQLAnywhere 16.0 SP45 Build 2207 Releaqse Notes Information
I think that this phenomen may be related to this correction.
When you have an official account for support, you shoud ask this question using the account.(You must present the repro step of this phenmenon)
You may obtain useful information.
Thanks,
Atsushi