Focus screen blues

A while back I ordered a split-circle focus screen for my 350D. (I won't mention the vendor by name at this point because my issue is still unresolved and I don't want to prejudge the result.) I was getting frustrated with a very hunt-happy autofocus system (especially in low light) and was finding the manual focus option to be very difficult with the standard screen. Losing a lot of shots that I was sure I could get if I could only _see_!

The screen arrived a couple of weeks back and I procrastinated about putting it in, because the screens are very easily scratched and/or dirtied and next to impossible to clean. Now I'm wishing I had just left well-enough alone.

Long story short[er], the screen went in fine. But the viewfinder focus was wrong, because I had put it in backwards (it's hard to tell, OK?). So I flipped it. And it was still out, but closer. So I put the copper shim back in (the one they said you didn't need). And it was worse. And so on and so forth, taking the screen out a lot, having trouble placing it back in. And it got dirty. And scratched. And cleaning with isopropyl alcohol left a mark. And blah. I tried putting the original screen back, but couldn't get it to line up. At 2am I declared defeat, emailed the support address and went to bed for some fitful sleep.

I was so annoyed I didn't take _any_ cameras with me when I left the house today (well, except the one in my phone). As anyone who has seen me recently will know, this is highly unusual. I was that sad.

Support email came back and said I should try with the extra bits of sticky stuff to extend the shim. That made it worse. So I took out the shim. Better, but not right, and nowhere near good enough for manual focus (which was the point of this, remember?). I need to move the screen further back. Or make it thinner (tricky).

So, email to support again. I figure they'll either declare me incompetent, come up with some trick I haven't thought of (no, I'm not taking a scalpel to my camera!) or admit there's an issue and get me a screen that fits.

Hopefully I get some joy - I can see the potential of the split circle to really enhance my work and I can't wait to have a working one on my only digital body. Maybe shooting some film will cheer me up in the meantime...