[R-sig-dyn-mod] Problem with dede's lagvalue (deSolve)

Dear R dynamics community

I am trying to solve a dynamic model based on DDEs with deSolve?s dede solver. However, I am encountering problems understanding and solving errors related to the lagvalue function. Here?s the code:

----------------------------------------------------
library(deSolve)
supplydrive <- function(t, y, parms) {
   with(as.list(c(y, parms)),{
     #y[1] = demand
     #y[2] = price
     #y[3] = supply
     #y[4] = extraction rate
     #y[5] = production stock
     #y[6] = manufacturing stock
     #y[7] = in-use stock
     #y[8] = waste management stock
     
     #define delays
     #Extraction rate // s
     slag <- t - s
     if (slag <= 0) {
       e_slag <- y[4]
     } else {
       e_slag <- lagvalue(slag, 4)
     }
     #Stocks // l
     llag <- t - l
     if (llag <= 0) {
       s3_llag <- y[7]
       s2_llag <- y[6]
     } else {
       s3_llag <- lagvalue(llag, 7)
       s2_llag <- lagvalue(llag, 6)
     }
     #Price // tau
     taulag <- t - tau
     if (taulag <= 0) {
       pricelag <- y[2]
       dpricelag = 0
     } else {
       pricelag <- lagvalue(taulag, 2)
       dpricelag <- lagderiv(taulag, 2)
     }
     
     #waste and dissipation flows
     w1 = eta*y[4] + gamma*(1-eta)*e_slag#delay s<---
     w4 = theta*(alpha4*s3_llag + alpha7*s2_llag)#delay l
     d1 = lambda*y[5]
     d2 = lambda*y[6]
     d3 = lambda*y[7]
     d4 = lambda*y[8]
     totald = d1+d2+d3+d4
     
     #supply, demand, price
     dy1 = r*y[1]
     dy2 = c*y[2]*((y[1]-y[3])/y[1])
     dy3 = y[4] - (w1 + w4 + totald)
     
     #extraction rate
     if (dpricelag > 0)
       dy4 = y[4] * (dpricelag/pricelag) #delay tau
     else
       dy4 = z*dy1
     
     #stocks
     dy5 = y[4] - alpha1*y[5] + alpha2*y[6] + alpha5*y[8] - w1 - d1
     dy6 = alpha1*y[5] - alpha2*y[6] - alpha3*y[6] + alpha6*y[8] - alpha7*y[6] - d2
     dy7 = alpha3*y[6] - alpha4*y[7] - d3
     dy8 = alpha4*y[7] - alpha5*y[8] - alpha6*y[8] + alpha7*y[6] - w4 - d4
     
     list(c(dy1, dy2, dy3, dy4, dy5, dy6, dy7, dy8))
   })
}

yinit <- c(1, 1, 1, 1, 1, 1, 1, 1)
times_sd <- seq(0, 200, by = 0.1)
parms_sd <- c(alpha = c(0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1),
                  tau = 120, r = 0.1, c = 0.8, s=2, l=1,
                  eta=0.2, gamma=0.3, theta=0.5,
                  lambda=0.01, z=0.2)
y_out_2 <- dede(y = yinit, times = times_sd, func = supplydrive, parms = parms_sd, method = "lsoda?)

?????????????????

This runs fine. However, if the times sequence length is increased to, say,

times_sd <- seq(0, 500, by = 0.1) ,

then I get the following error

Error in lagvalue(taulag, 2) :
illegal input in lagvalue - lag, 355.98, too large, at time = 475.98

However, this shouldn?t be the case because the conditional statements in the function should make sure that the lagtime is not to a time before the beginning of the simulation (t=0). Is this a memory issue? How could I go about solving this issue?

Many thanks,
Nicola