I've used PayPal a number of times, and not had a problem. My dad uses it on Ebay and in making other transactions online pretty regularly still. I am sure problems can happen, though. Most of the problems I've encountered with online transactions, though, is trusting who you're sending money to--and that's not an issue here.
As soon as I get myself signed up on Paypal with my own account, I'll be sending a donation.