IRasterBand.ComputeStatsAndHist() .. Attempted to read or write protected memory

Hi I have one very strange error when i try compute statistics for my Raster (only happens whit FGDB Raster). It happens when i overwrite raster (when i create new raster everything is OK). Any Ideas? thanks

Dim pRasterCol As IRasterBandCollection
pRasterCol = pRaster
Dim pBand As IRasterBand
pBand = pRasterCol.Item(0)
pBand.ComputeStatsAndHist() 'ERROR

ERROR = "Attempted to read or write protected memory. This is often an indication that other memory is corrupt."

I create raster like this>

Dim copyRaster As ESRI.ArcGIS.DataManagementTools.CopyRaster = New ESRI.ArcGIS.DataManagementTools.CopyRaster()
Dim gp As ESRI.ArcGIS.Geoprocessor.Geoprocessor = New ESRI.ArcGIS.Geoprocessor.Geoprocessor
gp.OverwriteOutput = True
gp.AddOutputsToMap = False

copyRaster.in_raster = pRaster
copyRaster.out_rasterdataset = pOutputPath
copyRaster.nodata_value = -9999
copyRaster.pixel_type = "32_BIT_FLOAT"

gp.Execute(copyRaster, Nothing)
gp = Nothing
copyRaster = Nothing