7.0.4 is the latest version of CS5.

What color is the text?

Ir looks like an overprint problem, and it also looks like you might be suffering from White Box Effect. Take a look at InDesignSecrets » Blog Archive » Eliminating the White Box Effect and see if anything applies.

Was the text set in ID, or is it imported?

I suspect that "text box" was actually an imported graphic (if it was, it would show in the layers panel when selected), or possibly pasted paths from Illustrator.

If it is a graphic there's a reasonably good chance that the type was set to overprint originally, and that it wasn't changed when the color was changed to white. White is not an ink color (except in special situations when used as a spot color ink), but rather the absence of ink on the paper (which is why it is called [Paper] in ID), and when you print no ink on top of anything what's behind shows through. This is a common problem with disappearing white type, but it's nearly impossible to create overprinting white directly in ID (Blending modes, I think, being the exception).

It bothers me though, that you said the type showed up in overprint preview as overprint white should disappear. I can't tell for sure what the problem is without seeing the file, but if you want to send me the original one that doesn't work I'll take a look and see if I can figure out what happened. I'll send yo a Private Message with directions and an upload link you can use, if you want to.

Paul,

I'm the moderator here, and your response, in my opinion, was out of line. Daniel is a long-time vounteer here, and I see no evidence to suggest anything in your accusations.

In fact I would say your first post, made some rather egregious presumptions that your problem and that of harooki2 were the same, all evidence to the contrary. In his case he said that the type was visible in overprint preview, which categorically eliminates the possibility that it was set to non-printing in the attibutes panel. Though he might have phrased it better, Daniel was suggesting that had you followed the suggestion  to check overprint preview and reported that the text (or whatever) disappeared, the first suggestion that any of us here would have made would be to check the attributes for non-printing. In fact, that's precisely why he suggested that check in the first response to this thread, to eliminate that as a possibility and quickly establish how complex the problem is.