Significant difference between contains and containstable?

I have a full-text index created upon a column of type varchar(max) with filestream enabled. The filestream contains data such as JPG's, TIF's, PDF's, and XML's (although this is mostly irrelevant to the question, I believe).

I have two queries that I've created that allow me to search upon the index.

Full-text search #1--

select
  parentObj.ObjectID as 'GroupingID',
  parentObj.Name as 'Grouping',
  childObj.ObjectID as 'FileObjID', 
  childObj.Name as 'FileName',
  fs.FileStreamID
from dbo.dat_FileStream fs
inner join dbo.dat_Object childObj
    on fs.ObjectID = childObj.ObjectID
inner join dbo.dat_Collection c
    on fs.ObjectID = c.ObjectID
inner join dbo.dat_Object parentObj
    on c.ParentID = parentObj.ObjectID
where contains(FileStreamData, @srchTerm)
    and parentObj.ObjectTypeID = 1
ORDER BY 'Grouping'

Full-text search #2--

select
  KEY_TBL.RANK,
  parentObj.ObjectID as 'GroupingID',
  parentObj.Name as 'Grouping',
  childObj.ObjectID as 'FileObjID',
  childObj.Name as 'FileName',
  fs.FileStreamID
from dbo.dat_FileStream fs
inner join containstable(dbo.dat_FileStream, FileStreamData, @srchTerm, 1000) as KEY_TBL
    on fs.FileStreamID = KEY_TBL.[KEY]
inner join dbo.dat_Object childObj
    on fs.ObjectID = childObj.ObjectID
inner join dbo.dat_Collection c
    on fs.ObjectID = c.ObjectID
inner join dbo.dat_Object parentObj
    on c.ParentID = parentObj.ObjectID
where parentObj.ObjectTypeID = 1
ORDER BY 'Grouping'

The only significant difference between the two full-text searches is query #1 uses contains and query #2 uses containstable.

My problem is that the two queries do not always yield the same results. For example, were I to search on the phrase "Independent contractors", query #1 would yield a result set of 10 different documents (PDF's and XML's), while query #2 would only yield a result set of 6. This seems to be the rule: query #1 always yields a few more than query #2, and query #2 always yields the exact same matches that query #1 does.

Query #1 - search on "Independent contractors" yields:

4262    AAA-00-12  4561 AAA-00-12.pdf   4235
4316    AAA-00-15  4753 AAA-00-15.pdf   4427
4316    AAA-00-15  4754 AAA-00-15.xml   4428
3873    AAA-00-19  4784 AAA-00-19.pdf   4458
3903    AAA-00-22  6795 AAA-00-22.pdf   6459
3953    AAA-00-24  6899 AAA-00-24.pdf   6563
3953    AAA-00-24  6900 AAA-00-24.xml   6564
4842    AAA-00-9   4905  AAA-00-9.pdf 4577
4842    AAA-00-9   4906  AAA-00-9.xml 4578
4057    AAA-0001   4260  AAA-0001.pdf 3936

Query #2 - search on "Independent contractors" yields:

19  4262 AAA-00-12   4561  AAA-00-12.pdf    4235
126 4316    AAA-00-15  4754 AAA-00-15.xml   4428
126 4316    AAA-00-15  4753 AAA-00-15.pdf   4427
116 3873    AAA-00-19  4784 AAA-00-19.pdf   4458
125 3903    AAA-00-22  6795 AAA-00-22.pdf   6459
57  3953 AAA-00-24   6900  AAA-00-24.xml    6564
57  3953 AAA-00-24   6899  AAA-00-24.pdf    6563

Thanks for any help that I receive on this!!