Repeater ClientID Change after DataBind() (BUG?)

[Iain]

A placeholder a repeater and a couple of textboxes walk into a
bar....haha...

No, Seriously, I have a placeholder, a repeater, the repeater
itemtemplate has a textbox in it, and a submit button to tie it all
together. So, in the page_load event I bind to a simple array using:

rep.DataSource = new string[4];
rep.DataBind();

At this stage the textbox clientid's are myRepeater$ctl00$textBox,
myRepeater$ctl01$textBox etc...

So now I move the repeater inside the placeholder using:

myPlaceHolder.Controls.Add(myRepeater);

and the clientid's have changed to: myRepeater$ctl04$textBox,
myRepeater$ctl05$textBox etc.

Any idea why the clientid's have been changed?

Iain