Front Street:For those new to the business of hedge funds and asset management, funds have rules such as not allowing a single stock to be more than a certain percentage of their portfolio. Considering that Front street bought 8 million shares at 25 cents according to filings on Feb 19th 2010 and probably also participated in the 25 cents financing in Oct 2009, then for them to be selling stock at the 50 cent rage and higher makes perfect sense as PTA has become to big a part of their portfolio (also, any required hold period as part of the financing they participated in in 2009 would have expired and allowed them to sell stock). Again, no fund will allow any one stock to probably be greater than 5% of the value of their portfolio - therefore it makes perfect sense for Front Street to do the selling they did that netted them more than 100% return.
There has been no other insider selling for more than a year back but rather insider buying at prices above 40 cents per share by real insiders. Front Street is not a real insider but since they had owned at least 10% of the securities, then TMX considers them an insider.