AFAIK, the version numbers work as follows:

1.0 - original RTW release
1.1 - RTW with first patch
1.2 - RTW with second patch
1.3 - RTW with the third patch which came bundled with BI
1.4 - Original BI (unpatched)
1.5 - RTW with fourth patch
1.6 - BI with its first patch

The "1.6" patch also included the 1.5 patch, so installing it would leave you with RTW 1.5 and BI 1.6.
So if you are seeing 1.4 I think it means you still have the original, unpatched 1.4 BI. You might want to check what version your RTW (imperial campaign) shows - if it's 1.3 then the patch didn't intall properly, while if it's 1.5 then perhaps you accidentally downloaded the 1.5 patch instead of the 1.6?