Meta-Publication Bias?

A problem with evaluating anything in research is publication bias. That is that research which has a statistically significant result may be more likely to be published, and more likely to be published in more widely read journals. Sometimes this is called the file drawer problem - if you want to know about all the research that has been published in an area, you don't just need to find and read all the journal articles, you need to read all the articles that didn't get published and sit in file drawers.
Research has been carried out on publication bias, to see if this effect has been occurring. However, the British Medical Journal has an article this week on publication bias in studies of publication bias.
The researchers looked to see if studies of publication bias that found publication bias were more likely to be published - a sort of meta-publication bias. They did not find any such bias, but they said that the power to detect such a bias was small, because of the small numbers of studies.