@Both of you.
(1) Have you tried force clearing your browser?
Windows - IE or FF - crtl F5
Macs - FF - Cmd-Shift-R
(2) WordPress usually works well with IE7, FF2 and Opera 9. Safari and IE6 have issues. If you haven't upgraded your browser that is always worth a try.
If force clearing your browsers does not work then your issues will apparently require staff assistance. This means you will have to send in a feedback (light blue button) located on the top right hand corner of any blog page. Please give them as much information as possible including your Operating System and version of it as well as your browser and version of it.
However, there are two other considerations. The first is how many entries you are trying to import. drmike recommends that 200 be your maximum. The second is time of the day and net usage. It's best if you do not attempt importing at a time of the day when the internet is at it's peak usage. The best time seems to be very early in the morning before the US eastern time people are placing heavy demand on the net.