Hrm, that’s odd, as we weren’t seeing that issue on 64 bit in our testing.
However, Joe just redid all the repository metadata – can you try it again? (assuming you haven’t already gotten things installed using the workaround you mentioned)
I’m now able to check for updates as normal. I have a 64-bit system too, btw.
Ubuntu Linux 14.04.1 Webmin version 1.791 Virtualmin version 5.02.gpl Kernel and CPU Linux 3.13.0-85-generic on x86_64
Interesting that though the error message was about a file not being received, I found I could get it in browser and wget it just fine. Though it did not contain the phrase it was looking for.