I've had the same problem for ages, don't know what changed to make it start. One thing I've noticed is on the files that skip if you right click them and click 'create AAC version' (might be a different format depending on your import settings) the new song you created will have a total time of 4:37 every time (it only seems to happen to songs longer than 4:37).
I'm curious if anyone else gets the same thing.
My solution which seems to be working so far (someone already suggested this) is every time you import music into iTunes use a different application (I use MAX) to convert the files to a different format (it seems to be MP3 thats the problem so I use Apple Lossless but its up to you) and then import them to iTunes. To find all the songs that are already acting up you could select all, right click and create AAC version. This will duplicate every song in your iTunes library and then you'll have to look through every one for songs that changed to 4:37 long and reimport. For all the other songs you'll have to delete all the duplicates so this could take quite a while (to change the format of the new versions, the option is in iTunes preferences>general>import settings (bottom right) if you're using iTunes 11.4).
Hope this helps
I'm curious if anyone else gets the same thing.
My solution which seems to be working so far (someone already suggested this) is every time you import music into iTunes use a different application (I use MAX) to convert the files to a different format (it seems to be MP3 thats the problem so I use Apple Lossless but its up to you) and then import them to iTunes. To find all the songs that are already acting up you could select all, right click and create AAC version. This will duplicate every song in your iTunes library and then you'll have to look through every one for songs that changed to 4:37 long and reimport. For all the other songs you'll have to delete all the duplicates so this could take quite a while (to change the format of the new versions, the option is in iTunes preferences>general>import settings (bottom right) if you're using iTunes 11.4).
Hope this helps