I have a Profit Sharing Plan effective for the entire plan year. that adopted a 401(k) effective 11/01/02 (calendar year plan). In my adp test I use compensation from 11/1/02 - 12/31/02, correct? Do I have to cap comp. earned from 11/1/02-12/31/02 at $200,000 or do I prorate the 200k for 2 months? I think I do need to prorate but I am confused about the effect of having the ps plan in place for the entire year.

For adp testing purposes, you can use any definition of compensation which meets the requirements of IRC 414(s). An allowable exclusion is comp paid prior to plan participation, so as long as your document reflects an effective date for employees to make pretax deferrals as of 11/1/2002, I don't see any problem with counting compensation for that time period for adp testing purposes.

You don't have a short plan year, so compensation paid during that time period is not subject to any prorated reduction in the IRC 401(a)(17) comp limit. You may use $200k.

Some documents have restrictions on the ADP test parameters. While the regulations clearly permit you to use compensation while the 401(k) feature was in effect, the document may require otherwise. It might make sense to read it to see what flexibility you have.