[Lazarus] External SIGSEGV when trying to use data module components

[brian]

Hi all, 

I'm writing an application which uses Firebird embedded. My setup is
currently Lazarus 1.2.6 with FPC 2.6.4, but I have the 1.4 RC3 files
to install if anybody thinks that should make a difference. I'm using
the AMD64 version of Lazarus and Debian 7.6 multihome, with i386
architecture also installed. 

My problem is a simple one to describe - the program compiles
correctly, but the moment I try to do anything with the objects in the
data module, I get an immediate 'external SIGSEGV'. When I say do
anything with them, this is as simple as adding a line of SQL to a
query. 

The program compiles OK, of course, and removing gdb from the mix and
recompiling just gives me the same error, but now the ASM window pops
up at a different address. 

Any help gratefully received, because I don't know what else to try...


Brian.