The recently released patch for Nightlife isn't perfect according to Maxis. Several users have reported that since installing the patch, students in University (only in combination with the University expansion pack of course) are having problems when class overlaps with the final exam. The game will then make the Sim act as if he or she is going to class rather than the exam, and will mark the Sim has not having attended the final exam. This also hurts the grade of the student in question. Maxis is working on a new patch to solve this problem.

Two work-arounds exist right now. If your student still has enough time before the final exam, you can make them visit a community lot. When returning at home, the clock will not have advanced much, but the time until the final exam has ticked on during the community lot visit. This should make the final exam be before class starts, and thus they won't overlap anymore. Another solution, provided by Maxis, is to move out the Sim and then move them back in. This will reset the time to 8am, without changing the countdown timer to the final exam.

It's unsure if the bug also appears in Open for Business, which has recently gone gold and possibly contains fixes similar to those in the latest Nightlife patch. See the BBS Thread for more details about the problem. The work around is called temporary, until Maxis releases a new patch, which makes it very plausible that they're working on a new one. An estimated date for the release of the patch has not been given. Thanks to Fabian from SimsZone for the link, and Mirena68 on their forums for a community lot workaround.