In reply to cookieman:
Assuming you have the standard (black powder-coated chromaloy) bars, not the spring (silver uncoated steel) bars, they really should not bend much. Any flexing should happen where the bar joins the frames, mostly the front frame. Though with an accordion fitted, I guess it might be hard to tell the difference.
Do you have unreasonably large feet? that can make bending worse.
I guess when front pointing, the points lift up, and the crampon bends down away from the boot. It probably won't come off, the new classic binding is almost impossible to get right off when done up correctly. But if it becomes loose enough for the toe of the boot to ride up over the posts, it'll still spoil your day. Adjusting the crampon so that the posts are hard up against the boot front and back could help, though getting a perfect fit is impossible if you're half way between settings. The new-matic binding (with a heel clip) might help too, as it pushes the boot forward hard against the front posts. As might super asymmetrical bars, if your boots are quite curved - because you'll go from three to four posts in contact.
If you do decide to try and stiffen them up, you need to be sure whether it is the bar bending or the joints between bar and frame. Not much you can do about the former, other than custom bars. If the latter, then bolting the bar to the frame will do the trick, but there's not a lot of metal to be drilling holes in. A clamp holding the two together might be better than bolts.
Or, of course, go back to G14s for ice. Strap-on G12s aren't really in their element on grade V ice. That's not to say they are unsuitable, but being nearer their limit any incompatibility with the boot is going to be more noticed.
Post edited at 20:32