Martha,

Just a wild guess , but does your UDF is dynamically linked to any Kylix
shared libraries (rather large) ? If so, maybe it's not present in memory
when UDF is selected throught TCP/IP connection and someway coudn't be
found by firebird user (assume your server is running as firebird user).

Maybe try to locally run isql as firebird user , connect using
'localhost:your_databasepath_or_alias' select UDF and look if it causes
trouble.

If You select UDF locally , is it working good even after reconnect all
connections.


Best Regards
Bogusław Brandys