Swing Low Exits

[TWA7663@xxxxxxx]

I discovered that TradeStation "does not always" properly exit at the last 
swing low with a strength of 1 when the following code is used:
{
If MarketPosition = 1 then ExitLong at SwingLow(1,L,1,50) stop;
}
I had decided to "not" use the above code because it is possible that TS will 
not find a swing low within the length (50) that the user specifies.  This 
will result in erroneous system results.  However, when the length was 
properly set and the maxbarsback were not a issue, I noticed that TS would 
"still" occasionally fail to exit on the proper bar.  I had noticed this 
after I was having trouble with code that I had substituted for TS's 
SwingLow(1,L,1,50).  I went back to SwingLow(1,L,1,50) and made sure the 
length and maxbarsback were OK to test the same exits that were failing with 
my substituted code and I I got the same errors.

Here is the exit code I substituted for SwingLow(1,L,1,50).

{
Vars: LowLow(0);

If L[2] > L[1] and
   L[1] < L then
begin
   LowLow = L[1];
end;

If MarketPosition =1 then ExitLong at LowLow stop;
}
Can someone tell me why this occasionally exits incorrectly?