Randy,

Is everybody using SP1?

I just ran this code and it printed 8

dimension lax[5,5]
lax[2,3] = "ABC_123"
? ascan( lax, "ABC_123" )

If you hold the shift key down while you click ok in the Tools, Options dialog you can dump all your settings. Here are mine:

SET TALK OFF
SET NOTIFY OFF
SET CLOCK OFF
&& RecentlyUsedFiles = 12
SET COMPATIBLE OFF
SET PALETTE ON
SET BELL ON
SET BELL TO '', 1
SET SAFETY OFF
SET ESCAPE ON
SET LOGERRORS ON
SET KEYCOMP TO WINDOWS
SET CARRY OFF
SET CONFIRM OFF
SET BROWSEIMECONTROL OFF
SET STRICTDATE TO 1
&& TabOrdering = 1
&& ResWidth = -1
&& ResHeight = -1
&& GridHorz = 12
&& GridVert = 12
&& ScaleUnits = 0
&& FormSetLib = 
&& FormSetClass = 
&& FormsLib = 
&& FormsClass = 
SET EXACT OFF
SET NEAR OFF
SET ANSI OFF
SET LOCK OFF
SET EXCLUSIVE OFF
SET MULTILOCKS ON
SET HEADINGS ON
SET DELETED ON
SET OPTIMIZE ON
SET UNIQUE OFF
SET CPDIALOG ON
SET REFRESH TO 0,5
SET ODOMETER TO 100
SET BLOCKSIZE TO 64
SET REPROCESS TO 0
SET COLLATE TO ""
&& SCCProvider = 
STORE "C:\PROGRAM FILES\MICROSOFT VISUAL FOXPRO 8\SCCTEXT.PRG" TO _SCCTEXT
&& ProjectHookLib = 
&& ProjectHookClass = 
&& CrsBuffering = 1
&& CrsMethodUsed = 1
&& CrsWhereClause = 3
&& CrsFetchSize = 100
&& CrsMaxRows = -1
&& CrsNumBatch = 1
&& CrsUseMemoSize = 255
&& SQLDispLogin = 1
&& SQLTransactions = 1
&& SQLConnectTimeOut = 15
&& SQLIdleTimeOut = 0
&& SQLQueryTimeOut = 0
&& SQLWaitTime = 100
SET DEFAULT TO c:\vfp8app\misc
&& TMPFILES = c:\docume~1\david\locals~1\temp
SET PATH TO c:\program files\microsoft visual foxpro 8\tools\;
&& HelpTo = c:\program files\microsoft visual foxpro 8\dv_foxhelp.chm
&& HelpCollection = 
SET HELP ON
SET HELP COLLECTION 
SET HELP TO "c:\program files\microsoft visual foxpro 8\dv_foxhelp.chm"
&& ResourceTo = c:\documents and settings\david\application data\microsoft\visual foxpro 8\foxuser.dbf
SET RESOURCE ON
SET RESOURCE TO "c:\documents and settings\david\application data\microsoft\visual foxpro 8\foxuser.dbf"
SET SYSFORMATS OFF
SET SECONDS ON
SET CENTURY ON
&& CurrSymbol = $
SET CURRENCY LEFT
SET CURRENCY TO "$"
SET HOURS TO 24
SET DATE TO AMERICAN
SET DECIMALS TO 2
SET FDOW TO 1
SET FWEEK TO 1
SET MARK TO ""
SET SEPARATOR TO ","
SET POINT TO "."
&& DebugEnvironment = 1
SET TRBETWEEN OFF
STORE     0.00 TO _THROTTLE

>We had an unusal problem with ASCAN yesterday.
>
>ASCAN(laArraay,'ABC_123') returned a 0 (zero) when ABC_123 was in the array.
>
>ASCAN(laArray,'ABC') returns a 5
>
>ASCAN(laArray,'ABC_') returns a 0
>
>So we know it's the underscore.
>
>It was a five dimensional array, and ABC_123 was in the 5th row, 1st col.
>
>This was unusual because ASCAN returned the position for 2 other developers on other machines. We've tried changing all of the envirionment variables that we can think of that might affect it, but no luck. (SET EXACT, SET ENGINEBEHAVIOR). We aslo tried passing some of the flags in ASCAN, but nothing seemed to work on this one machine.
>
>Everyone is running VFP 8.
>
>Thanks,