R help - Oct 2008 - StructTS hang?

I was wondering if I could get some advice on how best to diagnose a problem
that I am having with StructTS. To illlustrate the problem I have generated a
rigged time series:

genseq <- function()
{
  x <- numeric(4*365)
  s <- seq(as.Date("2005-01-01"), as.Date("2008-12-31"),
by="month")
  ob <- as.vector(s[c(10,22,34,46)] - as.Date("2005-01-01"))
  oe <- as.vector(s[c(11,23,35,47)] - as.Date("2005-01-01"))
  for(.index in 1:length(ob))
  {
    x[ob[.index]:(oe[.index] - 1)] <- 1 
  }
  return(ts(x, frequency=365))
}


series <- genseq()
series <- ts(c(series, rep(0, nextn(length(series)) - length(series))),
frequency = 365)
fit <- StructTS(series)
plot(cbind(fitted(fit), resids=resid(fit)), main = "StructTS
decomposition")


This call to StructTS seems to hang indefinitely. 

Any ideas?

Thank you.

Kevin