Thanks Lord of the Rings - I went completed the java update, repaired permissions and tried LW from a test account ... alas no success.

I also tried deleting the LW preferences file but there is none - I guess because it not getting past the initial boot-up stages and so is not actually creating a preference file.

I'm using a new MacBook as follows

Model Name: MacBook
Model Identifier: MacBook5,2
Processor Name: Intel Core 2 Duo
Processor Speed: 2 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 3 MB
Memory: 4 GB
Bus Speed: 1.07 GHz