Further to this message;
I have received some invaluable assistance from the New IT support forums (thank you!) but I am still some way from feeling confident in how to proceed - Guides tend to be for other plugs, slightly different goals, etc.
To now, I am aware that it is possible to upgrade U-Boot, Kernel *and* RootFS all from JTAG, serial *or* within Linux. The first approach requires the JTAG module which I do not have and would like to avoid purchasing for full price. The second approach requires a serial cable which I do not have. The cost here is not an issue but not knowing exactly what cable and/or connector to use, etc, is a slight issue. I'd consider this option if I had to, but; The third approach is the riskiest but does not require anything new. I'd like to try this approach and obtain the JTAG module or serial cable if things went pear-shaped.
Now the simplest (and my preferred) reinstallation approach is the one outlined here: http://www.newit.co.uk/forum/index.php/topic,1810.msg5118.html#msg5118
Can anybody give a step-by-step guide for how to flash U-Boot, Kernel and RootFS from within Linux using the images (and possibly the same approach?) as in that article? Is it possible to use that approach 'as is' with mtd-utils? Again, if somebody could give some fuller instructions (or further reference material for me to read) I would be particularly grateful.