[solved] Slic3r 097 no Slic1ng properly on basic STL

I hope this isn't something really obvious but I am finding that some parts won't slice properly with slic3r at all.

The example I've shown in the two images is the bar clamp from the Prusa Mendel. hundreds of thousands of these must have been printed and no one else has complained about the STL file that I can tell.
I am using the Slic3r 0.9.7 that is bundled with Repetier host on Win7-64 english.
The STL imports and displays correctly in repetier host but when I slice it there are big sections missing.

I've looked through the Slic3r settings so many times and none of them seems to have any effect. Can someone point me to what is wrong?

Edited 1 time(s). Last edit at 12/12/2012 07:50AM by mikep-nz.

Oh I forgot to add there's an error message that is in the Slic3r output
00:24:42.412 : Warning: The input file contains a hole near edge 82.000000-84.000000 (not manifold). You might want to repair it and retry, or to check the resulting G-code before printing anyway.
00:24:42.427 : => Processing triangulated mesh
00:24:46.127 : The model has overlapping or self-intersecting facets. I tried to repair it, however you might want to check the results or repair the input file and retry.

Come to think about it this probably explains why it doesn't slice. But how is it everyone else has managed to print this part and I can't?
What's the big secret?

OK. As often happens, the moment you post something the answer appears.
This post nicely explains how to use netfabb to clean up an STL file that is reporting errors.
Problem solved.

http://forums.reprap.org/read.php?4,170019,170021#msg-170021