What would you suggest someone do if they expect their 1998 AGI might exceed $100,000 and they have already converted a tradional IRA to a Roth IRA in 1998. In this case, the person undid their initial conversion and reconverted after 11/1/98, thus maxing out their conversion limits for 1998.

The limit is on reconversion (and even then there is no limit, just a limit on how many reconversions can lower the tax burden), not on recharacterizations.

You can always recharacterize, up to the due date, with extensions, of the tax return.

If you're over the limit, recharacterize.