[R] lattice smooth

[Troels Ring]

Dear friends - I have a data.frame hh with columns
Na ID fit  time

135 13  134.7945   60
133 13  132.9084  120
131 13  131.0848  180
129 13  129.3372  240
127 13  127.5546  300
126 13  125.8162  360
124 13  124.1836  420
123 13  122.6077  480

When I use lattice
xyplot(Na+fit~time|ID,hh,type=c("smooth","g","p"),
auto.key=list(lines=TRUE))

the curve for Na after time 240 takes some wild swings, and a warning is 
issued

Warning messages:
1: pseudoinverse used at 482.1
2: neighborhood radius 242.1
3: reciprocal condition number  0
4: at  360
5: radius  14400
6: all data on boundary of neighborhood. make span bigger
7: There are other near singularities as well. 14400
8: pseudoinverse used at 482.1
9: neighborhood radius 242.1
10: reciprocal condition number  0
11: at  360
12: radius  14400
13: all data on boundary of neighborhood. make span bigger
14: There are other near singularities as well. 14400

Otherwise for the whole dataset of 16 pigs it works quite OK - but only 
this pig number 13 makes troubles.
I wonder what occurs.
Best wishes
Troels

-- 

Troels Ring - -
Department of nephrology - - 
Aalborg Hospital 9100 Aalborg, Denmark - -
+45 99326629 - -
tring at gvdnet.dk