Indeed DBD::Sybase fails on the execute with a somewhat appropriate error message, although the text of the message would seem to indicate that DBD::Sybase doesn't handle this situation as well as it could:

DBD::Sybase::st execute failed: Server message number=201 severity=16 
+state=2 line=0 procedure=*00001600000000_d028c5 text=Procedure *00001
+600000000_d028c5 expects parameter 
Invalid pointer param number 4, pointer value 0x0
, which was not supplied.
Server message number=201 severity=16 state=2 line=0 procedure=*000016
+00000000_d028c5 text=Procedure *00001600000000_d028c5 expects paramet
+er 
Invalid pointer param number 4, pointer value 0x0
, which was not supplied.
[download]

I should probably see if the parameter binding code could be made somewhat more robust...

Michael