Never used paypal via Amiga as I recall.
I just logged in with IBrowse 2.4, WINUAE (AmigaSYS4 to be exact!)
It let me in and showed me my last 2 transactions.
In Preferences, I have the defaults set to load all images, allow javascript yes, frames support yes. (Not via the menu strip pull downs, but within Preferences->Settings)
I had to set it up this way to get OutlookWebAccess to work to access an MS Exchange server.