Hi Neil,
Please try upgrading to LimeWire 3.8.4, the newest released version.
If that doesn't work, could email me the full crash report (generated from 3.8.4), at
sberlin@limepeer.com , that'd be useful. Also, if you can detail exactly what you do that causes it to crash (is that what you mean by 'disappear'?), that'd be great.
Thanks,
Sam