Nut and bolt problem with front strut installation

[PHL]

I installed Bilstein Sport shocks and H&R Sport springs this afternoon on my 1995 Sport. When I was replacing the top bolt that is fastened with a nut to the king pin on the left strut (No. 5 here http://www.realoem.com/bmw/showparts...21&hg=31&fg=10), the bolt stopped moving with 3mm, give or take, to go. The nut is flush with the washer, but the bolt is stuck. I used an impact wrench to tighten it, and it didn't budge. Tried to remove the bolt, and it didn't move. (Yes, I held down the nut with a box wrench while doing both.) Then I tried again, and again, tighten and loosen. No luck. There was some Loc-tite on the bolt. As I had to leave (using my in-laws garage to do auto work), I tightened the nut with the impact wrench. The bolt didn't move a bit, even when I removed the box wrench.

At the moment, the front suspension is all together, and I took it out for test drive. The bolt doesn't look like it's going anywhere, but I'll check it again tomorrow.

In the meantime, any ideas as to what happened? Should I take it into a garage and have them remove the bolt? Anything that I should try myself?

The rest of the installation was completed, except for this bolt.

P.S. Thanks to andyman for his instructions in the Knowledge Base, very helpful. I'll add some comments from my experience, probably in this thread to keep the thread alive.