On SunOS with DB2 V7.1, the following SQL command works fine :
INSERT INTO dbit1 ( dbit1_key, dbit1_dt, dbit1_dta ) VALUES ( 1, d1, d2 )

dbit1_key TYPE INTEGER
dbit1_dt TYPE DATE
dbit1_dta TYPE TIMESTAMP

d1 and d2 are DATE
d1 : 12/24/2001
d2 : 11/14/1989

With DB2 V8.0 (no fixpack), it gives me the following error :
SQL statement error number -6372 (-301).
[IBM][CLI Driver][DB2/SUN] SQL0301N The value of input host variable or parameter number "" cannot be used because of its data type. SQLSTATE=07006

Any idea ?

Did you look for APAR's included in any of the 6 fixpaks for version 8 that have been released. The base code is usually a bit buggy.

I've find some stuff bu nothing that match exactly my problem.

I'm surprised it worked in v7. I don't believe you can assign a DATE to a TIMESTAMP. Try using TIMESTAMP function.

I should have be more specific about. It works when I throw the SQL statement througth a 4GL application.

So the problem should rather come from here, from the DVM used to run the application.