How does certificate-based encryption solve key revocation problem?
The revocation status of a certificate is application dependent, meaning that if the application under which you perform the encryption or decryption does not check for revocation status with the CA, then you may still proceed and encrypt or decrypt the message.
You should consider the loss of a private key of a certificate as a loss of your password in a symmetric encryption environment. The same argument applies to PKE.

The same applies to a signature verifications: a well behaved program should check the revocation list when verifying a signature, but this depends on the application developer interests. I can verify a signature as a valid one in certain programs without consulting a revocation list at all.
You can easily test this, for example, by checking on a signed windows program on a computer that is not connected to the internet (look at the Digital Signature tab in the Properties pop-up dialog box of a signed executible): The digital signature of the program would be reported as OK (if indeed nobody messed with its bits) even though the revocation list has not been consulted.