Can you show us a SMART report?
That said, I can't imagine that hacking the drive is in any way responsible for the "weird" SMART errors. If the owner of the drive used HDDHackr to make the drive look like another model, eg a Fujitsu, then s/he should have saved an UNDO.BIN file. This file contains the original firmware MODs 0D and 02. In fact the firmware is not really modified in any essential way, only the drive's identity is altered.
If the owner cannot supply the UNDO.BIN to reverse the hack, then DO NOT be tempted to use an UNDO.BIN file from a different drive, even if it has the same model number and same firmware version. If you do, you will probably brick the drive. Instead, rather than un-hacking the drive, you can re-hack it, but this time you will be using the parameters of the original WD drive rather than those of a Fujitsu, etc.
The procedure is explained in the following thread at WD's forum:
http://community.wdc.com/t5/Desktop-Por ... d-p/393685