The tape format was changed from 11d onwards but you should be able to catalog the data again from 2010 and restore it. Make sure you run the inventory first then the catalog and then try to restore the data.
Shouldn't be too much of a problem. Catalog the tape in Backup Exec 2010, and see if it appears. You may have to change the date that you restore from if older than what is initially shown in the restore wizard.
I'd also suggest downloading the Backup Exec 2010 SCL for future reference...