Looks ok. What is full create-table statement used to create the tForms table (including all types and sizes)?
Your version of Texis uses the 32-bit API across the board, including file offsets, as indicated by the sole `-32' at the end of the version. It is thus limited to max 2GB tables (though with blobs you might reach 4GB because it's 2 files). Later versions of Texis for Windows -- with `-64-32' in the version -- still use the 32-bit API for memory etc., but use the 64-bit file API, and can thus create/access tables larger than 2GB.
Table creation is with this statement:
<sql db="$Updatedb" "CREATE TABLE tForms (FormID int, FormType int, TextBlob varchar(256))"></SQL>
In the scenario where index creation is failing the contents of the TextBlob sometimes approach 500 K. The total number of rows in the table is about 80000. Many rows contain small amounts of text.
That KDBF error when indexmem is 5 is suspicious; what amount of free space does dir report on that directory? Check for and delete any old Tnnn* files left over from previous failed index builds.