CIVIRM adding characters to Event name on submission to Paypal, payment received but shows as "pending, incomplete payment"
"1679-2049-3V2016 - Modul..." is the contactID and contribution ID stored within civi respectively, followed by the event title, but concatenated to fit the total length allowed for the Item title.

This seems to be a change in the new version. Quite why this has changed from  just the event title, I'm not sure, but I guess its been added to help reconcile who the contribution is from and what for to make it easier to match up paypal and civi records.

The second issue is different theres a resolution coming out for this for Joomla (see https://issues.civicrm.org/jira/browse/CRM-18245) - maybe it will fix drupal as well.