When you alter a column by changing a timestamp value to 0, the resulting Alter Script is not generated.
An empty window is shown, where the script should be.
Timestamp(0) is not supported in v5.0.4
WORKAROUND:
None.
STATUS:
Waiting for fix in a future release of Toad for DB2
Fixed in upcoming beta release:
http://toadfordb2.com/beta.jspa