I read this regarding 30-day extensions for 60 day Thai tourist visas:

"A tourist visa can be used to stay in Thailand for up to 30 days or up to 60 days and can be extended by 30 days at the nearest Immigration office. Normally there is a fee of 1,900 Baht (as per 2008-01-17) but until March 31st 2011 they are free."

Source: http://www.thaivisa.com/272.0.html

Is this referring to the 30-day extension being free, or the original 30 or 60-day tourist visa being free? (I know the 30/60-day visa is currently free due to the fee waiver in place until March 2011).

I have tried googling to find out, but can't be sure - a few snippets I've read here and there would indicate that the 30-day extension is currently being charged at 1,900 Baht.

The original tourist visa is free.

All extensions at immigrations within Thailand are 1900 baht.

My last extension - as of December - was the usual 1900b, as was the one before that. They are just referring to the fees for the visa itself, which has been free for a little while now.

Yes, all extensions are 1,900 Baht.