clientupdate The client did not report any logfile data and rrd-data.log error updating

I am running xymon 4.2.3 on a solaris platform. I am deployed to 300+ clients and all is working. Today I decided to use clientupdate for the first time. The two clients I configured to receive the updates were updated but now the 'msgs' test on both clients returns "No log data available" and "The client did not report any logfile data". All other tests are still working.

in a probably unrelated issue, I also see persistent messages in rrd-data.log:

2009-11-25 10:47:16 RRD error updating /export/home/xymon/data/rrd/<hostname>/ifstat.mac.rrd from <IP>: illegal attempt to update using time 1259167636 when last update time is 1259167636 (minimum one second step)

any idea what is going on?

thanks