SIMPLE-TYPE-ERROR: 4294970108 is not of type (UNSIGNED-BYTE 32) when setting slot CL-ISAAC::B in #S(CL-ISAAC:ISAAC-CTX :RANDCNT 0 :RANDRSL #(2751073604 1637694640 2011656142...

[tdrhq]

On Lispworks. The library is generally stable, but occassionally after many months of running the random number generator gets into this state. I'm calling this from multithreaded code, but protected by locks.