I think even in the good old days when the land price was $2000/ha something had gone wrong with MIS already and because of that some of those companies collapsed.
GTP's operating cash flows actually always maintained positive before collapse, including in its last annual report for the year ending 30/9/2008. (see http://www.asx.com.au/asxpdf/20081229/pdf/31fdj4k36wdm1m.pdf, page 60) So it looks indeed like a Ponzi more than anything else.
GTP Price at posting:
12.0¢ Sentiment: None Disclosure: Not Held