I suspect that your draintile outside is either clogged, broken, or leaking due to age or improper installation. Water will sit in the block wall itself for a long time before it starts showing up inside, but these marks are telltale signs!

Get a few local waterproofing companies to give you their opinions. There is a lot of good info I've found on the www.basementquestions.com site or you can try www.basementquestionsandanswers.com

and maybe www.nawsrc.com good luck, fixitguy