Vetrimaaran unhappy with Simbu?

Silambarasan aka STR is said to be the reason behind National Award winning director Vetrimaaran dropping a works

hop he had planned for his forthcoming film 'Vada Chennai', which has Simbu and Rana Daggubati in lead roles.

"Vetrimaaran wanted to hold a workshop before the film hits the floors, since he wants the actors to be familiar with the script and the characters they play. But he had to cancel it at the last minute, after STR suddenly left for the US for his upcoming love anthem," sources say.

The director is currently waiting for the actor to start the workshop, it is said. To be produced by Dhayanidhi Alagiri under Cloud Nine Movies banner, 'Vada Chennai' is a movie which will chronicle the lives of people in the northern parts of Chennai.

Meanwhile, when one of his followers on Twitter put a posting which read "VetriMaaran has postponed the workshop of STR's VadaChennai to a future date, due 2some difficulties", the director reacted sharply, saying: "It isn't STR's Vadachennai. Silambarasan is acting in Vadachennai which doesn't make the film STR's."