and now...not back on track

OMG-I am so frustrated.  So...this week, runs are going well then yesterday about a mile into it...bam, shins!  Same as last week.  I did back off the pace and this new pace this week was not all that hard.  totally felt great.  So, I am thinking its my shoes.  I tend to have shoe drama.  I just bought these shoes.  These are the shoes I sported in Memphis during St Jude Marathon.  I had problems late in the race with lower legs locking up but I attributed it to poor training.  But I did move from the 2100 series of Asics to the Kayano's for Mercedes Marathon.  No Problems.  Then I just went back to the 2100 series and bam...problems.  Even had a twinge of the leg lock up feeling in a long run and now two days of shin issues.  Maybe its all in my head but I am ordering Kayanos today and just have to suck it up and use my whole paycheck for the upgrade.  As long as my legs are happy....