This appears to be fixed now. I had recently installed the "Quick Cache" plugin for wordpress which was messing with the downloads. If you still have problems please let me know.
I am really sorry about this, I thought I had it fixed a few months back but it seems to have returned. Thanks to Alan or helping me track down the problem. It could be IE or it could be the plugin I am using for downloads. I will have another look into it tomorrow and hopefully find the cause.
In the meantime, Firefox seems to be fine and I guess other browsers too.
Oh, and I am still working like mad to get the new website up… this one is specifically for the addins and I am very excited about it. It is surprising how long the little details take though!