Memory allocation error when use SCORR

[Boyin Huang]

I have a script plotting time series for spatial correlations. The script
works fine but failed after several executions. The error message was
Memory Allocation Error:  grid storage
Data Request Error:  Error for variable 'taux.1'
Operation Error:  Error from maskout function
Operation Error:  Error from scorr function
I tried to undefine variables but it does not help.
Any ideas to solve the problem?

--------------------------------------------------------

rc = gsfallow("on")
'reinit'
'clear'

fname1= '/u/wx52bh/gpfs/qscat/gr/gcv_QSCAT_monthly.ctl'
fname2= '/u/wx52bh/gpfs/gdas/data/gdas.1x1.monthly.ctl'
fname3= '/u/wx52bh/gpfs/R1/flux/flx.gau.gr.mean.y1979-2007.ctl'
fname4= '/u/wx52bh/gpfs/R2/flux/flx.ft06.gr.mean.y1979-2007.ctl'

'open 'fname1
'open 'fname2
'open 'fname3
'open 'fname4

v1 =            taux.1
v2 = 'maskout(-'taux.2','v1'+9000)'
v3 = 'maskout(-'taux.3','v1'+9000)'
v4 = 'maskout(-'taux.4','v1'+9000)'

'set x 1'
'set y 1'
'set time jan2001 dec2006'
'define var1= scorr('v1','v2',g)'
'define var2= scorr('v1','v3',g)'
'define var3= scorr('v1','v4',g)'

'd var1'
'd var2'
'd var3'