Strange Behavior After Upgrade To 1.5

After upgrading from 1.4 to 1.5, I notice some strange behavior the last couple of days. Piwik is currently tracking 5 sites. I noticed that for each site, there was 1 day that it said 0 visitors visited. When I look at the details for that 0 day, I see the data for another website that is being tracked. For example, on June 19, Website_A supposedly had 0 visitors, but when I look at the data (i.e. keywords), it shows the data for Website_B for that day.

Search (with phpMyAdmin e.g) for the day and idsite in the piwik_archive_numeric table for june (piwik_archive_numeric_2011_06).

Result e.g.

3973 	done 	5 	2011-06-19 	2011-06-19 	1 	2011-06-19 23:57:18 	1

delete the row. The statistics will then be calculated again and fix the error.