There's a slider for the Blender Foundation, who make Blender, but not one for me. Unless I'm very much mistaken.

I see that deleted comment... :) I'm not on the list unfortunately.

Ehwot? I thought you were bone parenting it to the character's armature, not its own! No wonder things went mental when you unparented.

Use the Clear Parent operator but this time choose "Keep Transforms". Then re-parent it to the armature normally.

I assume that "weapon4_0" is a bone on the character model?

It sounds to me like you don't have matching bone names. If you upload the blend I can see what's going on for myself.

If you want to reposition the object, parent it to the armature normally. then the Tools will export its position relative to the armature.

In Source, inter-model parenting is done through bone names. Parenting in Blender has no effect whatosever on the model's parent in Source.

The solution to your problem is removing the bone parent. Why don't you just try it and report back?

Remove the bone parent. To make the character hold the weapon all you need is a weapon bone with the same name as a character bone; the parent of the Blender object is irrelevant.

If you're desperate to see the weapon moving correctly in Blender you can always parent the weapon's armature to the character bone. :)

I'd like to fix the game importer crash if I can. Could you send me your DMX and/or blend file(s)?

Are you using qc_eyes.exe? It should be in your engine folder.

Look for general Blender/Source tutorials. They'll cover the Source Tools.

What are you having trouble with specifically?