You'll need to delete your database from "%LOCALAPPDATA%\Btcd\data\mainnet", so the chain download starts over.  The issue is your existing database is corrupt (hence why you're seeing the issue looking up a specific transaction), so only upgrading the code alone won't fix it.  However, the root cause that led to the corruption to begin with is what updating the code resolves.  I should have mentioned that in my original response.

As far as the size, the last released msi was built with the Go 1.2 runtime, and I'm guessing you built the latest with the most recent Go 1.3.1 run-time, so a difference in size is expected.  12MB (x86) and 15MB (x64) is what I have as well with the go 1.3 runtime.

EDIT:

I just rebuilt to verify:

x64
09/18/2014  10:13 AM        15,415,296 btcd.exe

x86
09/18/2014  10:15 AM        12,524,544 btcd.exe