Old MFM controller on a PCI bus machine

I haven't played with MFM hard drives and controllers in a LONG time (about 10 years now) so I have some questions. I'll start off easy. Should there be any reason an old 16-bit ISA MFM controller won't work properly in a Pentium-class PC with ISA and PCI slots? I imagine I would just have to configure the BIOS to reserve the proper interrupt (I believe it's 14, correct?) for the MFM controller. I did all this but the MFM controller wreaked havoc on the system. It killed the on-board floppy disk and IDE controllers (not physically killed but basically disabled them and the system couldn't boot). I'm trying to determine if there is a natural conflict before I venture forth with this configuration. This may be a problem related to the PC I'm trying to plug the card into because there are other oddities with the IDE controller that is preventing the system from booting with 4 hard drives installed (2 per IDE interface). It halts after it auto-recognizes the drives on the primary controller. Weird. Anyway, any insight would be appreciated. I'm going to do more experimentation in the meantime. I'll get another PC with ISA and PCI slots to work with, and will also find an old 386 to test the MFM controller on to make sure it is working fine.