Primary key creation - strange message (SQL server7 - SP3)

[Mitesh]

Hello,

When I try to create a primary key for a table(alter table tablename add primary key( columnname)), I get a message
" SQL 1918. ( Index (key=2) is being rebuilt)."
Does any one have a clue, as to why do I get this. The primary key does get created ,but my application stops working, after getting this message.

Thanks,
Mitesh