Help – Weird post time issues!

I have noticed an issue in my installation and I do not know why it is happening.
This is hard to explain clearly so please bear with me.
If you go to http://www.200feet.com/blog and look at any date where I have made more than 1 post to the blog. (There is a calendar at the bottom of the left hand sidebar that you can browse to a specific date with)
For example – if you browse to the date 21 April 2007, you will notice I made 3 posts to my blog on that day – but if you look at the detail at the end of each post it should say for example “Filed under: See it!, Softball
on April 21st, 2007 at 4:31 pm by Tugs”.
However, only the last post for each day includes the time. each of the earlier posts on that day show for example “Filed under: Blah, Shoulder op, Softball
on April 21st, 2007 at by Tugs” (notice the time is missing between ‘at’ and ‘by’.
This happens for any day where I have made more than 1 post to my blog.
But why?
At the time I publish each post the time is listed – but when I post a 2nd or 3rd entry for that day the older times disappear!
can anyone help?