Thanks for your comments. Yes I may be dancing in the dark here. I
looked at the firbird-devel list and it specificially says not for
user questions - I don't consider myself building or porting Firebird
YET (I wanted to do Solaris, but got buried by other things - this
project I am working on - which I hope will put the product all over
the place).

Anyway, I upgraded (rpm -U) on the Fedora platform

FirebirdCS-1.0.3.972-0.i386.rpm -> FirebirdSS-1.5.2.4731-0.i686.rpm

So using CLASSIC not SS (as stated in original message), I believe
(perhaps foolishly) that the conf file is read each time something
starts up - it acted that way - I changed things and made things better.

I am using /opt/firebird/bin/isql to test my UDF and the line in conf
reads

UdfAccess = Restrict UDF

The entry point I was testing (one of many is "get_bit(...)") as is
the C name for such - this module has been working since Interbase
V3.2 up to Interbase 6.5 as well as in Firebird 1.0.3. Yes the case
matches as does the entry for "properCase(...) which use to work too
and is in this library. But in case, you think I lost it entirely -
here tis the declaration in both places

short EXPORT get_bit(long *number, short *which) {
(in UNIX/LINUX -> #define EXPORT /*nothing*/)

declare external function get_bit (integer, smallint) returns smallint
by
value entry_point 'get_bit' module_name 'SISudf';

In 6.5 IB and 1.0.3 Firebird the module would be in
/opt/interbase/UDF/SISudf or /opt/firebird/UDF/SISudf. In 1.5 tis not
happy till the name is /opt/firebird/UDF/libSISudf.so with the above
declarations, but then the entry point is not found.

By playing with the name, I got it to say "entry point not found" as
opposed to something that the server administrator would not allow me
to access.

Thanks for the advice.