HELP: Blobsize Parameter in BDE Admin missing !

Hello !

We have a wierd problem with one of our BDE installations.

If we create a new ODBC DSN (SQL Server), an alias is created by the BDE
Admin, so far so good. You can edit the alias and set it's property,
also the BLOBSIZE property, it is visible.

BUT: After closing and reopening the BDE Admin application and clicking
on the newly created alias, the BLOBSIZE property is not visible anymore
??!! We had a similar problem some years ago and I cannot remember how
we solved it.

What we tried:
1) Reinstall MDAC 2.6
2) Reinstall BDE 5.x
3) Redefinde DSN
4) Redefine BDE Alias

but nothing helped, the BLOBSIZE parameter disappears after the first

Any help greatly appreciated