Parsing error -8 when update-clause used with nextval

Hello MaxDB-Experts,

I'm using MaxDB 7.7 via JDBC.

When using PrepardedStatements the following insert works absolutely great using the sequence.nextval (seq_syncid is a regular sequence):

     insert into s_entity(A,B,C,D,E,sequenceID) values(?,?,?,?,?,seq_syncid.nextval)

BUT when I'm using more or less the same command:

     update s_entity (A,B,C,D,E,sequenceID) values(?,?,?,?,?,seq_syncid.nextval) where (F = ?)

it fails stating:

     SQLException: [-8]: Execution failed, parse again

     SQLState:     I0008

     VendorError:  -8

Any ideas, any help from you guys is really highly appreciated.

Chris