actually, unpatching does not help... it makes things worse.
imagine this scenario,
1. at firmware location A, the original value is "01".
2. a patch called turnmyphoneinto007phone is supposed to look for value "02" in that same location and replace it with "12" in location A but seeing that the value "01" is found instead in that location because its a different firmware, a warning is issued. lets just say you ignore the warning and continue patching it.
3. now location A has the value of "12". what happens after flashing is that it keeps rebooting your phone, that's definitely not what you want, so you panic and think that by undoing the patching process, things return to normal.
4. using the undo patch feature makes the patching program find and restore the value that you changed in location A previously after messing things up. it successfully finds the value "12" (because you already patched it to that value) but instead of changing it back to "01" it changes it to "02" because that's what the patch believes was the original value!
after this, you should already know the result... :D