Graphics problem solved
The problem was PHP 4.3.4 (and 4.3.6 BTW) was not compiling GD with JPEG support, even though the jpeg option was turned on in config. I needed to download JPEGSRC-6b and compile that, then manually specify the location during config of PHP. JPEG-6b was installed into /usr/loca/lib so that was the path I specified for the PHP compile, i.e.
--with-jpeg-dir=/usr/local/lib
and everything works. Annoying about the bundled GD support not installing the JPEG option when compiling PHP!
I am still working on the top_bar.tpl issue. I tried the code from sdl (below) (although the attachment would not appear or download for me, I needed to copy the wiki page) but the top bar images still get overdrawn by the left/middle columns of tiki when viewed in Mozilla. Any more ideas?
Thanks.
James