Wierd Table -- Aaargh!

Hello, I am having some really strange problems with one table. JUST that table. Occasionaly, users will complain saying that the order entry program is bogging down. Invariably, it is because of this ONE table. A query that normally takes a second will take 10. It is using a unique index on 3 columns for the query. I've tried dropping & recreating the index, clusturing it, bchecking the table & nothing works. The only thing that gets it back to normal is unloading the table, dropping it and recreating and reloading. There doesn't seem to be any pattern as to when it will happen. Sometimes it will be fine for a month, sometimes for a week. I've replaced the disk it was on, for other reasons, so I don't think thats the problem. It only happens on this table. It is heavily used, but there are other tables with more usage. Thank you. Please respond via mail Perplexed Pete