A SQL_ID by any other name... Same SQL / Different Tools / Different SQL_ID

I have been trying to chase down the same SQL being submitted against the same 10.2.0.4 Solaris database from different query tools used in our organization. I have been striking out when trying to match up with SQL IDs.

I connected with 5 different tools (including SQLPLUS on 2 platforms) and submitted the following 4 lines of SQL:

SELECT *
  FROM EMP, 
       DEPT 
 WHERE EMP.DEPTNO=DEPT.DEPTNO

The whitespace doesn't show in this format but the SQL was constructed with no spaces after the end of lines 1 and 4 and a single space character after the EMP and DEPT lines.

In each tool I tried to execute with a ; or / at the end of the statement and luckily got the same SQL_ID out of each so at least that syntax difference I can ignore.

ToolSQL_IDv$sql.sql_fulltext observation:
SQL Developer 3.0.02 on Win3201xkza6wk1sydLooks same as input including whitespace
SQLPLUS 10.2.0.4.0 Solaris3jt52v806qzu6Trailing spaces removed from each line
SQLPLUS 10.2.0.1.0 Win323jt52v806qzu6Trailing spaces removed from each line
PL/SQL Developer 8.0.4.1514 Win32 54vxryr83c1pw Looks same as input including whitespace, OPTIMIZER_ENV_HASH_VALUE does differ from other runs
Toad 9.6.11 Win32 gc3kk1r8ydrgw Looks as if single space character was added to the end of last line

Full details from v$sql for these 4 unique SQL_IDs available here:
http://ba6.us/content/2011-07-21-SQL_ID_ClientTest.html

I would revert to trying to match on SQL_TEXT field but even there I am seeing some white space differences.

So looking at sql_fulltext I did notice some whitespace differences between SQLPLUS and Toad - so that explains the different SQL_ID there. But I can't detect any differences between SQL Developer and PL/SQL Developer. Am I going crazy or is this each tool submitting the statement different enough that it causes a change in SQL ID?

-Dave

Update: The Execute SQL screen in Oracle Enterprise Manager did give me the same SQL_ID as one of the tools above, but I need to find my notes again to verify which one.