Q: MacBook Pro sometimes stuck at Apple logo

Hi!

I've tried searching the forums and googling for a solution, but so far I have not had any luck.

A few days after the release of Mavericks, I upgraded my trusty pre-unibody 2008 Macbook Pro directly from Snow Leopard.

Overall, things have worked great, except for a few odd applications that stopped working

However, since the upgrade, my Mac sometimes fails to boot (every third boot-up or so)

It gets stuck at the Apple logo with the "spinner" beneath it, and while stuck, the temperature rises and the fans slowly gets louder.

If I force the Mac off by pressing down the power button for 5 seconds, and power it on again, it boots like it should.

So while this hard-reset is a reliable workaround, I would much rather find a proper solution to this problem.

What could be causing this weird behaviour?

Any help is appreciated!

(PS. My setup is kinda unusual, I boot OS X from a SSD in the expresscard slot.

But as mentioned before, the bootup issue started after upgrading to Mavericks.)