Full-Text In SQL 2005

Hello everyone,
I've got a little question - wich drives me absolutely nuts by now :).

I'm trying to optimize my full-text search since a while now.

Scenario:
Full-Text Table:
id - int - primary key
srcID - varchar(30)
srchField - varchar(150) - FULL-TEXT INDEXED
src - varchar(15)
updateStamp - timestamp

Records in Table: ~ 4480000

To get my results I have to link the srcID-Field to another table.

But for performance Testing, two queries
LIKE VERSION:
SELECT srcID FROM fulltexttable WHERE srchField LIKE '%an%' GROUP BY srcID ODER BY srcID DESC

1. Running Time: 5 seconds, returns 921315 rows
2. Running Time: 5 seconds, returns 921315 rows

FT VERSION:
SELECT srcID FROM fulltexttable WHERE CONTAINS(srchField,' "an*" ') GROUP BY srcID ODER BY srcID DESC

1. Running Time: 14 seconds, returns 443676 rows
2. Running Time: 8 seconds, returns 443676 rows

If i do a search wich returns less records, full-text is a lot faster - but on big recordcounts it seems the LIKE query is faster? Is that possible???

Anyone any ideas?

Thanks in advance