single horizontal hairline crack in stucco
 

i am looking to bid on a stucco home about 16 years old in Houston, TX. The home has a single horizontal hairline crack in the stucco, about 4' ft off the ground. This crack runs about 60% of the house; the other 40% has windows etc, & the stucco is not cracked. There r no cracks in the inside walls. The bankrupt homeowner says it is real stucco (as opposed to synthetic stucco).
I am a attaching some pics showing the crack.
Any opinions if this hairline crack is a serious issue? what might be the cause?
I hear Houston has soft clay soil, so wondering if it is settling of the house?
Can crack be fixed? Wondering how to proceed?

http://img64.imageshack.us/img64/9660/dsc00005u.th.jpg
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http://img196.imageshack.us/img196/8...00046sg.th.jpg
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http://img6.imageshack.us/img6/9413/dsc10034.th.jpg
http://img858.imageshack.us/img858/8793/dsc10032.th.jpg
http://img705.imageshack.us/img705/2113/dsc10031.th.jpg