As long as its fermenting and finishes up close to where it should then I wouldn't worry about it.
Sometimes I don't get much krausen, sometimes its rushing out the blowoff tube. Like I said, no biggie as long as the yeast do their job.
EAC - 5/2/14
Growing Hops in Key West, FL....
: Spanish FlyPA
: Bourbon Chocolate RIS, Helles Lager, Best Bitter
: Sour IPA, Blueberry Espresso Brown, Imperial Session IPA
: The HBT Sweaty Fat Guys Cigar club