On Fri, 30 Jul 2010 12:09:29 -0700 (PDT), Part timer
wrote:

On the label, Philips recommend using short cable
lengths to one end of the tubes. What is the reason for this? I assume
something to do with 30kHz. How short is short?

Usually 1m for the "short" pair, 2m for the other. Only really an
issue if the unit is mounted outside the fitting (not unusual in
display lighting).

Anything else I should watch out for apart from isolating the fitting,
double checking work, etc?

Usually a simple job, you may need to drill a hole for a self tapping
screw to hold one end of the ballast as they are longer than the
standard one.