i also had problems when i tried to download when using a Download manager because it used multi connections, So after waiting about 30mins the 404 error went away and the link worked again so next time i set my Download manager to 1 connection and it worked fine.
Also titeguy3 i have been experimenting with different compressions on the files in your installer + updater and found winrar proberly isnt the best choice of compressor,
here is a picture of your updater recompressed into different outputed files
http://img168.imageshack.us/img168/4624/differencesincompressio.jpgyour original on the left, next to that 7zip Ultra, next to that is one compressed with peazip using ARC compression.
ARC seems to give the best results on both the full installer and the updater,
(it makes the updater 309mb in ARC format and the full installer comes out at 1.56GB in ARC format which is a massive saving)
anyway just thought you might be interested.