They do seem to be inconsistent. A guy in the Chiang Mai Expats group had his frozen at the Airport Plaza branch on a O Retirerment Visa. Needs passport certified by Embassy to unfreeze it. Crazy.
They are tightening up on people using Visa Exempt and Tourist Visas to reside in Thailand - they are checking that people are tourists and not residents. There are visa options available.
Some nationalities do get more scrutiny ie their applications have to be approved in Bangkok and not a local decision approval is possible and there are examples.