Slow file open dialogue box

Hi,

I upgraded to Mavericks OS over the weekend and everything seems to work ok. The only thing I have noticed is that my when I try to attach a file in Mail the dialogue box opens and where previously files would immediately appear they now take several seconds, maybe as long as five, ten seconds.

I think I've noticed similar behaviour in other applications but Mail is the one I use the most in this way.

Has anyone else experienced this since upgrading to Mavericks?

Regards and thanks,

Dave.