Ugh, PC0 + PDP-8I problem.

I have just started to look at this problem but I don't like it already. Here we go: If I load a RIM paper tape into my 8I using (single step) it loads in fine. If I load in a RIM paper tape into my 8I running (no manual steps).. the data loaded is garbage , and may not even be in the right place. If I toggle in a program to test the "all 1s" paper tape it passes (both single step and running) If I toggle in a program to test the "all 0s" paper tape it passes (both single step and running) If I toggle in a *larger* program to read a "1s and 0s paper tape" it passes (both single step and running). [this is ones and zeros alternating] I have checked the strobe line with my scope at it appears normal. I have checked and re-aligned the paper tape reader and data coming out of it (in step mode) is okay. My next move will be to try and load 32 bytes from the paper tape reader into core (not the RIM loader, my own quick program). and Write a quick program to write various numbers to core and make sure the are written correctly. There are no other devices connected. It could be the data is improperly strobed at high speed (adjacent holes on either side of the actual byte being read in are allowing enough light through to trigger the photo detector). I have the gain up quite a bit to strobe the feed hole.... but not enough to screw up the above three tests. Any suggestions???????????????? john