Issue when connecting external HDD

Hello I have a problem when connecting my external hard drive on my Mac Book Pro, if connected and all the partitions have loaded on the mac, and then i load photoshop or another program it takes ages for it to load, is there any reason as to this I have updated to the latest of Snow Leopard, i found out it was the hard drive because when i disconnect it my program loads fine but this is getting a bit frustrating as everything hangs when i plug it in, is this an issue with snow leopard or something else?

thanks

It sounds like an issue with photoshop. Check the preferences. Is it trying to use an external as a scratch disc? Or is bridge trying to index the external?

Hi mrplow,
Thanks for your reply but I am also getting the issue with other programs such as Dreamweaver etc and not just the adobe applications.
thanks

Ok.
Check spotlight preferences and make sure that's not indexing the drive