If it worked once, but subsequent runs fail, I would consider moving the scratch space directory. As ArcMap and Spatial Analyst processes data, the working directory fills up with data from the processes. If changing that directory does not solve the analysis, I would consider running the tool locally, to avoid sporadic network differences with Esri GRIDs across the network. If that does not solve the issue, then placing a Support call to check out the differences in your processing syntax. I would recommend against names that have symbols or start with numbers and paths with too many spaces or special characters.