System Objects Problem

I wonder if anyone can help ...

Today I tried to create another non-clustered index on a table. This
failed as I apparently already had 249 non-clustered indexex on the
table. Looking at the definition of the table there were 90 or so
indexes already defined and not 249. (For those of you who quite
rightly think 90 indexes on a table is a little over the top, I hasten
to add that this is a third party CRM system called "Siebel" which comes
with it's own database). However, examining the sysindexes system
catalog I find that there are indeed 249 entries, but that many
(possibly all) of them have names of the following type:

'_WA_Sys_XYZ_356BF102'

where 'XYZ' is a column on the table in question.

Looking at the same database across our DEV/TEST/PROD environments I
notice that these system like index entries are not consistant. The
names and number of entries differ. I've tried creating a new table
from a script generated in EM and no such indexes/system objects are
created.

I'm confused. What are these things. I can't drop them, sp_helpindex
doesn't refer to them. Examining the sysindexes/sysindexkeys catalogs
appears to suggect that the indexes have columns but no rows/entries.

I've got around the immediate problem by deleting one of these entries
from sysindexes and I've been able to create the index I wanted. All
seems well, but is this likely to cause a problem ?

Thanks in advance

Laurence Breeze