i think that most of the problems are due to some known PTC sites who turned scam. they tarnished PTC to paypal transactions. paypal became aware of such things ... I guess only those who retained reputation including clixsense will be the only allowed pay per click programs with paypal transactions ... and if a site does not offer paypal as a means for cash out and deposit ... you have to be cautious ... salute to clixsense for making its members feel secured ...
sorry for my english