Has anyone seen the following warning message when applying dipole correction (self-consistant) in castep?

Why do these messages appear and how can I fix them?

+---------------- MEMORY AND SCRATCH DISK ESTIMATES PER PROCESS --------------+
| Memory Disk |
| Model and support data 146.5 MB 392.1 MB |
| Electronic energy minimisation requirements 56.1 MB 0.0 MB |
| Geometry minimisation requirements 62.8 MB 0.0 MB |
| ----------------------------- |
| Approx. total storage required per process 265.4 MB 392.1 MB |
| |
| Requirements will fluctuate during execution and may exceed these estimates |
+-----------------------------------------------------------------------------+
 
WARNING: Ewald dipole correction: require orthorhombic cell for isotropic dipol
e correction
- hence turning correction OFF