Severe popup spoiling the realism: defrag?

After a few days of testing with verhy short flights, I finally got the settings I could live with. ;) So yesterday I started flying around for real. I have autogen to Extremely dense because I just love to see all that detail. Now I already read (a.o. in one of Phil's posts or his blog) that popup has become more obvious with SP1. But I have to say that it's more than that... it has become very bad... I expected things to popup in the great distance but they popup even pretty close! While landing somewhere near Marseille yesterday, trees kept on popping up during the final approach, up to touchdown (after which I couldn't see into the distance anymore...). It completely ruined the feeling of being there. I did not have this at ALL before SP1. Popup is a problem that has plagued many games but the last few years things have gotten a lot better. But this is a very bad example of popup... Now I did defrag my hd with the Vista defragger. I know there seem to be better programs. I tried Disktrix's defragger once, but it took already an hour or so before about 10% percent was analyzed, and I didn't have the time to keep it running any longer. So before I take the plunge and do it again (by letting it work on my hd while I'm at work... and in bed.... and at work... and in bed.... ;) ) I'd like to know if this is something that can be solved by defragging or if this is something I have to live with... I remember Phil saying popup will be adressed in the DX10 patch (well, they would look at it), so it is a known issue. So I wondered if there is ANY change of getting rid of it or not... Seems that's not the case...