The posting is good Dubz. We're quite casual here although more information would have been very helpful.
Not sure this is a recipe problem Joe, but who knows.
I have a feeling these batches have not been well taken care of and were bottled with little aging. Which bottles taste which way? Does the stronger batch taste boozy as well as the lighter one? Does the stronger batch taste watery as well as the lighter one?
Since I have little information about your batch let me talk a bit more in general.
1.
When a mead is young and hasn't aged much it will go through cycles. One week (or however long it's cycle is) it will taste good, another week it will taste not so good... I think this is more pronounced when bad fermentation techniques are used. Since you have split the batch into bottles the bottles will be going through these phases at different times. While some bottles will be going through one part of a cycle, other bottles will be going through another phase. I.e. all bottles might be alternating between boozy and watery and it might only be your impression that they separated.
2.
When a mead is not aged in bulk you will get inconsistent taste between bottles. Again I think this is more pronounced when poor technique is used So it might be that the bottles all started out the same but have aged differently. This will depend on the amount of aeration while racking to bottle, the condition the bottles were kept in (even small differences might have a long term effect)...
3.
Mead does seperate. At the very least if you rack a young mead, the mead towards the bottom of the carboy will have more yeast and other heavy particles which normally are racked off but in this case might have not had the chance. The bottles might seem the same now but if you wait a couple of months you might see that some bottles have a fine dusting of sediment while others less so. when suspended in the bottle these particles might give a different taste to mead. I think finer particles such as fusels might also separate (fusels cause the booziness taste and are considered a defect) although I have not found information about this. When I say separate I do not mean that all fusels will form a band, but rather that a higher concentration might be found at the top.
I think this has happened to me in the past because out of 72 bottles from a 54 liter batch which was aged over a year about 65 of them were fine to slightly fusely while around 7 were rocket fuel. Since I improved my technique this hasn't really happened to me again