This event may occur if you assign an I/O address to a COM port, and that I/O address is already assigned to another COM port. See ME112584
Variations exist such as ID:3 source: serial "user configuration data for parameter com1 overriding firmware configuration data" and ID: 36, Source: serial "while validating that com1 was really a serial port, the contents of the divisor latch register was identical to the interrupt enable and receive registers. The device is assumed not to be a serial port and will be deleted". Generally, all three errors pertain to misconfigured com ports. They are especially prevalent after creating a new com port. For instance, I added com 2 under nt 4 sp 6a to install my modem (the error is nothing to do with the make of modem by the way) and voila! I got all three errors! The error you get depends on the type of misconfiguration, typically the base I/O or irq is in conflict with another device or you are using the same configuration for both com 1 and com 2 resulting in ID 29.
Sometimes this error is created by winmodems installation (i.e. Lucent ltmodem).