A weird error I had reported to me last week turned out to be due to the use of underscores_in_sweep_names and (perhaps) to numbering crystals. This is most likely a side-effect of the heuristics I use to understand what is in MTZ files and such. Some recommendations:
* Don't use underscores in your project, crystal, wavelength, sweep names
* Don't use numbers for your crystal names
The second one is a problem as the CCP4 parser can get confused between datasets which are numbered and the number name of data sets. I would prefix it with P/X/W/S if you want to number things...