The advice to stop and rest is good advice. If you've been at it two months a rest might be good, take one or two days off and then resume the A/B schedule. Many aches and pains do go away and never come back.
However, you say you had leg problems before, so maybe there is something wrong. And RobertScott named the number one issue of the 21st century: weak glutes, with attendant poor hip mobility, which causes the knees to take up the slack, which they weren't designed to do, and weird injuries gradually develop.
At any rate, it is possible that powerlifting has
revealed an issue you already had, and the most likely candidate in us 21st century men is weak glutes.
Here is an article that discusses hip flexor pain. Although you are not complaining of that specifically, the article gives great form tips on squatting:
http://www.ericcressey.com/newsletter150html (If you don't know about Eric Cressey you are in for a treat, he's a genius).
Here is another recent article from T-nation that not only talks about glutes, it also opens with a photograph of musclar female glutes (a side benefit of many t-nation articles).
http://www.t-nation.com/free_online_art ... te_monster. Read through and try a lot of the light stuff on off days, and see if it doesn't make you generally feel better.
Glutes and shoulders, those are the big problems.