Thanks!
I agree 100%. If you can lift a weight for 5x5, how can it be 90% of your 1RM?
(I squatted 415 a few weeks ago, matching my 1RM. Squatting 375 for 5x5 would be pretty tough for me right now.)
There must have been more to it. I know with some programs, like 5/3/1, sometimes you're doing a percent of a percent, so, for instance, you might be doing 90% of your 90%, in which case you're really doing 81%.