Is there a clampdown on excessive Tourist Visa applications in Thailand?

Regarding Tourist Visa applications made in another Country. My gf has been making Tourist Visa applications coupled with an invitation from myself with a Retirement Visa. On each application my gf was given a 60 day permission to stay. But suddenly, at her last application for a Visa she was only given 30 days at the border, as if she was using Visa Exempt which she was not. We considered this to be a warning not to reapply. I thought that provided there was no indication of illegal working in Thailand we would not have a problem. Was this just an error by the immigration officer at the border of Thailand or is there a clamp down on excessive Tourist Visa applications?