Text box selection

[Opticrom]

Ok, so I'm new here but I've been using Ooo for several years now. My question to fellow users concernes text boxes in Impress. Here's the problem I'm having (and I did try searching to see if anyone else had already posted about this):

1) I create a text box in an Impress presentation, and write something in it.
2) If I click off the text box to go and do something else, I can come back to the text box and click on its edge, and little green squares appear along an outline of the box. I can drag the text box anywhere I want. So far, so normal...
3) If I save and close the presentation, and then open it again later, any text boxes I created earlier have changed - clicking on the edge provides some blue squares, but no outline whatsoever, and I can no longer move the text box. It's a bit of a hassle having to do a presentation all in one sitting...

Does anyone else have this problem? Is there a very obvious solution, and am I just a fool for not noticing it? In any case, I can see no rationale for this "feature". As appreciative of the OpenOffice.org project as I am, I must say I am frequently frustrated by Impress, and if I use PowerPoint on another machine it's like taking a massive sigh of relief (probably not a very popular thing to say around these here parts, I imagine...). I have very few problems with Writer, however.

I would be grateful for any help/comments on this issue.

Thanks,

Opticrom

[Opticrom]

P.S. Ok, so I've just realised that this is probably a problem with saving the presentation as a .ppt file as opposed to .odp. I was using .ppt, because I'll need it to be in that format for the actual presentation (as I imagine most people would who are doing school/work presentations etc). I suppose the workaround is to keep it in .odp until the last minute, but it still seems a bit strange to me. Is it some sort of bug?