The short term investments actually represent 61% of current assets. In addition they are expected to be liquidated for cash in less than 12 months.

From the Q: These investments are of high credit quality and the AAA credit ratings of the investments have been reaffirmed since February 2008. These instruments are collateralized in excess of the underlying obligations, are insured by the various state educational agencies, and are guaranteed by the Department of Education as an insurer of last resort. We have the intent and the ability to hold these investments until the anticipated recovery period which we believe will be less than twelve months.