R help - Jan 2011 - Error in M[, 1] : incorrect number of dimensions when trying to plot hexbin

Hello again,

I am trying to plot out activity regions the user did on the screen via 
plotting a hexbin. I have 20 users whose information i want to plot out 
and it stops in the user 16 with the message Error in M[, 1] : incorrect 
number of dimensions.  Any advice would be appreciated as i dont see why 
this error occurs on the data for the 16th user. All the other users get 
plotted out without a problem.

I am using the R 2.12.1 on W7 if needed. The user data is in the csv 
file attached to this mail. The R code is:

#libraries
library(RMySQL)
library(hexbin)

#user data
mycon <- dbConnect(MySQL(), 
user='root',dbname='test',host='localhost',password='')
rsUser01 <- dbSendQuery(mycon, "select 
a.userID,a.sessionID,a.actionTaken,a.timelineMSEC,a.durationMSEC,b.X,b.Y,b.Rel__dist_,b.Total_dist_
from `actiontimes` as a , `ulogdata` as b where a.originalRECNO = b.RECNO")
user01 <- fetch(rsUser01, n= -1)
user01[1,1]

#list of users
mycon <- dbConnect(MySQL(), 
user='root',dbname='test',host='localhost',password='')
listUser <- dbSendQuery(mycon, "select distinct userID from
ulogdata")
userList <- fetch(listUser, n= -1)
par(mfrow=c(5,3))
tmp6=rep("UserScatterActionRegion.pdf")
tmp7=paste(tmp6,sep="")
tmp7
#pdf(tmp7)
jpeg(file="UserScatterActionRegion.jpeg")
for (i in 1:20){

     x<-subset(user01 ,userID == userList[i,],select=c(X,Y))
     x
     bin<-hexbin(x$X, x$Y, xbins=100)
     part1=rep("Action Regions")
     nameFull=paste(userList[i,],part1,sep="")
     nameFull
     plot(bin, main=nameFull)
}

dev.off()