Increasing Response Time

Hello,

I am currently migrating a DB from Oracle to SQL Server (Microsoft SQL Server 2005 - 9.00.1399.06 (Intel X86))

I've used ssma to do the migration, and I'm reviewing the prodedures to check them. I have find a performance problem in one of them, which worked perfectly under Oracle, and I have tried lots of things with no luck, so I guess I need some help

I insert a row in a table, and the time it takes for this is fine, but seconds later I need to read the row, and this Select lasts 1-2 ms more every time. This process is repeated lots of times.

Every insert-select takes 200 ms when it receives the first data (including some other operations that are not increasing the response time), and 200 insertions later it takes about 500 ms, which is really too much, considering it keeps increasing.

The table has 25+ columns, and some of them contain varchar of 3000+ characters.

I make the select using 4 columns in the where part. One of them is a numeric, and the rest are varchar (no one is the primary key).

I've got a clustered index for the primary key, and two more non-clustered indexes. One of them refers to the columns I use in the Select, and the parameters are Fill Factor: 90, and Recompute Statistics Automatically.

I hope I explained properly...

Any ideas?