Pensieve Header: Bug: RowReduce for SparseArrays fails at ridiculously low sizes (fixed in 8.0.4).

{$Version, $MachineType, $ProcessorType}

L={a[4]+a[7]-a[10],a[5]+a[8],a[6]+a[9],a[2]+a[3]-a[4]+a[6]-a[7]-a[8]}

M=CoefficientArrays[L, Array[a,{10}]][[2]]

M // Normal // MatrixForm

RowReduce[M // Normal] // MatrixForm

RowReduce[M]// MatrixForm

1+1