A strange problem. I couldn't find "upcoming events" and "search forums" under "add a block" for a new course on the Moodle site I administer (version 2.6). I have used these blocks in other courses, and they still exist there. Below is a screenshot. The one on the left is what I see in an old course. The one on the right is what I see in the new course. I've checked that the "upcoming events" and "search forums" blocks are not in hidden view on the course homepage.
If it helps, the new course has a large number of participants (1000+), and the old one had about 350. The server hosting our Moodle site was upgraded recently. Other than that there have been no changes.
Any ideas?
Thanks,
Ravi