R help - Oct 2008 - Need Help using the OO package

Hi Henrik,
It would be great if you could help me out with my following problem.

I am trying to create a class like :

setConstructorS3("MyPTCM",function(tokenslist=0)
{
       extend(Object(), "MyPTCM",
       .gamma = 0.0,
       .rho = 0.0,
       .phi = 0.0,
       .tokenslist = tokenslist,
       .uniquetokens = unique(tokenslist),
       .numtypes = length(uniquetokens),
       .Nsq = numtypes*numtypes,
       .CONTEXTti = array(0,dim=numtypes),
       .CONTEXTtim = array(0,dim=numtypes),
       .ZEROVEC = .CONTEXTti,
       .MTF = array(0.0,dim=c(numtypes,numtypes)),
       .hIN = array(0.0,dim=c(numtypes,numtypes)),
       .tokencount <- 0);
}
)

Everytime I try to create an object of type MyPTCM, it gives me an error
saying
> b <- MyPTCM(tokens)
Error in extend.Object(Object(), "MyPTCM", gamma = 0, rho = 0, phi =
0,  :
       object "uniquetokens" not found

I have tried using this$.uniquetokens and just by referencing it with
.uniquetokens and other such techniques but to no avail.

I'm sure I'm making some basic fundamental mistake.
Any kind of inputs would be greatly appreciated.
Thanks in Advance,
Aditya