okay fellas (long time absence, considering a return...), i see you're having issues?
I dug up a working copy of 1.9 Beta 1b (btw, I'm the module author) from a working url, installed it on a XOOPS 2.2.3 test site, and after some tweaking of the settings, it's working great with Paypal Sandbox (paypal area to test IPN and whatnot without using real money). So, I can verify the module still works, even with XOOPS 2.2.3
There's a few issues though:
1. make sure your mainfile.php shows the COMPLETE url for your website (I noticed the installer just picked up the /xoops22 testsite directory of the url, without the actual domain), which caused errors in the donations module, preventing Paypal from finding your site
2. make sure you are using the PRIMARY email account for your paypal id. if not, the paypal transaction will not be recorded by the donation module (I need to check paypal dev docs to see if this has changed yet)
3. make sure your account is Verified with Paypal
Those are the 3 biggest solutions I can think of at the moment. If you want to use the paypal sandbox for testing, you must register at
https://developer.paypal.com/, create a Business acct with a fake email address and a Personal acct with a fake email address. Enter the Business email into xDonations, change the Paypal IPN url to the Sandbox url (it's a dropdown option in the Configuration), save.
Make a donation using your fake personal acct, you should see the IPN transaction completely process.
Post if you have issues/questions