[WINBUGS] - Issue - TRAP: undefined real result

#1
I am having an issue with WINBUGS when some of my priors are uniform. Here is the problem area:

Code:
 ## Set up A matrix ##
   A[1,1] ~ dunif(0,1) ## THESE TWO ENTRIES CAUSE THE PROBLEM ##
   A[1,2] ~ dunif(0,1)
   A[2,1] <- 1
   A[2,2] <- 0
   A[3,1] <- 0
   A[3,2] <- 1
    
   nu.inv1 ~ dunif(0,1)
   nu.inv2 ~ dunif(0,1)
   sigma.beta ~ dunif(0,1000)
   nu1 <- 1/nu.inv1
   nu2 <- 1/nu.inv2
   a1 <- nu1/2; b1 <- (nu1/2)*pow(sigma.beta,2)
   a2 <- nu2/2; b2 <- (nu2/2)*pow(sigma.beta,2)
   tau.beta1 ~ dgamma(a1,b1)
   tau.beta2 ~ dgamma(a2,b2) 

    for (j in 1 : J){   

	 ## Setup priors for betas ##  	
    	 B[j,1] ~ dnorm(0,tau.beta1)
  	 B[j,2] ~ dnorm(0,tau.beta2)    
      
     	 mu[j,3] <-  B[j,2]
     	 mu[j,2] <-  B[j,1]
         ## uniform priors cause issues here ##
     	 mu[j,1]  <-  A[1,1]*B[j,1] + A[1,2]*B[j,2]
 
     	 X[j,1] <- Y1[j]
     	 X[j,2] <- Y2[j]
     	 X[j,3] <- Y3[j]      
      
	 X[j,1:3] ~ dmnorm(mu[j,1:3],tau[,])  			
}
When A[1,1] and A[1,2] have a uniform(0,1) prior I get the TRAP, but if I switch them to normal(0,1) it is fine. If I try to truncate the normal though, I get the same error.

Any ideas?

Thanks