I have found a few in mission testing so far:
IBX-DEBUG => POF checksum: 0x0649f342, IBX checksum: 0xc58f499f -- "fighter02.pof"
WARNING: "Subsystem "communications" in model "fighter02.pof" is represented as "communication" in ships.tbl. Although FS2_OPEN 3.6 and later will catch and correct this error, earlier versions (as well as retail FS2) will not. You are advised to fix this if you plan to support earlier versions of FreeSpace." at modelread.cpp:604
IBX-DEBUG => POF checksum: 0x13d53078, IBX checksum: 0x57f8d8ef -- "bomber01.pof"
WARNING: "Couldn't open texture 'bomber01-00b' referenced by model 'bomber01.pof'" at modelread.cpp:2274
WARNING: "Couldn't open texture 'shieldhit01a' referenced by model 'bomber01.pof'" at modelread.cpp:2274
Model bomber01.pof has a null moment of inertia! (This is only a problem if the model is a ship.)
IBX: Found a good IBX/TSB to read for 'MX-50.pof'.
IBX-DEBUG => POF checksum: 0x8d6824ab, IBX checksum: 0x3141c987 -- "MX-50.pof"
DDS ERROR: Couldn't open 'wep-mx50-shine.dds' -- DDS was in an unsupported/unknown format