Dear kchipndoc,
As i know you can use your paypal account from different divice ( system ) but some time you may get error because as you know paypal always think about the security. Paypal want to protect the users account and wants to make every user safe.So you may get error.While using paypal you use from one system at a time.As i am also using paypal account from 2008 and some time due to same thing i get error .So i recommend you not to use same paypal at the same time from 2 system.
