Difference between execution time of a package

I've a package which was created in BIDS (2008), When executing it, the runtime duration is approximately 90 seconds.

I've deployed the package and connected to Integration Service engine via SSMS to run the package, the runtime duration was 20-25 (!) minutes.

I'm using 32 bit runtime env and SQL Server 2008R2

What can cause this abnormal behavior of the duration?

Thanks