Access xp vs access2k3

Hello, I have a bit of a wierd problem in that I have a database written in access xp and the users have all had new machines with office2k3 written on. The database has a search on it that works in access xp but not in access 2k3. I thought that it was completely backwards compatible. please can someone advise on this? the database is not overly big and has very few information fields but the same search that works almost instantly on access xp kills the machine in 2k3.

 

Not sure what you mean by "search". Do you mean a Query?

 

Yup just a standard query
searching for a list of names or anything else is almost instant in office xp but in 2003 hangs the machine.