How often is the database refreshed?

When a SD Card is in the slot, my Sansa Clip+ 4GB refreshes it’s database on every startup. Even if the SD Card is not changed. Depending on the number of mp3s on the card, this can last for some minutes. Is this normal?

Nope–not normal.  By any chance, is your microSD card at all loose in its slot?  The continual refresh can happen with a loose card–the player thinks the card is continually being inserted.

You might want to try and see what happens with a different card in the slot. 

If the issue persists, can you return the player and get a replacement with the seller?  Otherwise, are you still within the warranty replacement period (1 year U.S./2 years EU–and note that if you purchased via credit card, some cards have a feature that doubles the warranty period)?

And 1 other possibility:  try a reset of the player (hold the on switch down for 20-30 seconds) and reapply the latest firmware (see the firmware upgrade sticky thread at the top of the forum).