Issue with SSIS Custom Components - 64 bit SQL 2012

Question

Hello All,
Our SSIS packages built on SQL 2008 R2 make use of some custom components. These custom components are installed as part of an MSI. The dll's are copied over to the Windows/assemble [GAC Folder] and also to the Program Files(x86)/SQL Server/110/DTS/* folder.
The installation does not copy the dll's to the 64 bit program files folder.
X:\Program Files\Microsoft SQL Server\110\DTS
These packages are executed via SQL Agent jobs on a 64 bit SQL server and there does not seem be any issue.
Now we are upgrading our servers to SQL 2012 and we have a new installer for the custom components as well. The new custom components use .NET Framework 4.0 and when installed the dll files get copied over to the Ms.NET 32 bit runtime GAC folder and also
to the SQL Server DTS Folder in x86. The upgraded packages work only when we set the runtime mode to 32 bit. The packages successfully executes within the 32 bit dtexec utility, but when we try to run the same package using a 64 bit dtexec utility the
process errors out with a component failed to load message. The package moves data between two SQL Server instances.
The custom components have always been built for 32 bit runtime. I can run a older package through the dtexec utility (from the 64 bit folder in program files) and it does work without any issues. After the upgrade the package will only execute on
a 32 bit utility. can someone help me understand this issue?
Regards, Dinesh

Answer 1

Thank you Arthur.
i think we got the answer as well, as the .NET framework 3.0 installer copied the files over to the C:\windows assembly the dtexec utility [32 bit/64 bit] was able to load the components.
Now with the new installer the files are copied to specific runtime gac folders as Arthur has mentioned. The 64  bit  utility does not find the dlls in the GAC whereas the 32 bit version will find them.
Regards, Dinesh