There is no macrovision in blank tapes. That's not your problem (unless you are taping on old tapes - but I don't think that would happen either - once you recorded over stuff, you've effectively erased the macrovision).
These points in the tape - are they were you stopped or paused the tape while recording? If so, that might be the issue. Some software will freak out if you have a break in timecode. I don't see this as being the exact issue - that's usually only with professional grade. But it *could* be what is happening.
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"Nature has constituted utility to man the standard and test of virtue. Men living in different countries, under different circumstances, different habits and regimens, may have different utilities; the same act, therefore, may be useful and consequently virtuous in one country which is injurious and vicious in another differently circumstanced" - Thomas Jefferson, moral relativist