IMemoryBlobStream::LoadFromFile unknown Failure

[conquerorconqueror]

I'm trying to load into blob saved MxDocument file with simple code:

IMemoryBlobStream memoryBlobStream = new MemoryBlobStreamClass();
if (System.IO.File.Exists(fileName))
{
 memoryBlobStream.LoadFromFile(fileName); //Causes exception sometimes.
}

Exception: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Assembly : ESRI.ArcGIS.System
Class    : MemoryBlobStreamClass
Method   : LoadFromFile

System: ArcGis 9.2 with SP5 (Build 1450)

Any suggestions how it can be fixed?