Cluster lights come on sporadically

[word is bond]

The lights for my Speedo and Fuel gauge rarely come on right away. Sometimes, it's after 5 min of driving, sometimes 10, sometimes a half hour plus. Is this a symptom of something else going wrong, or just dying bulbs?

Edit: Smacking the dash seems to have no effect.

[Gregs///M]

Start with new bulbs, bad ones can have those symptoms.