You should be able to enter the correct budget amount in January on the budget tab and then apply that same amount to all the months going forward. Are you saying you were unable to do that? Or are you talking about showing future months actuals based upon the reminder?
edit. Assuming it is the later, I suggest you delete and re-enter the reminder for your spouse.
Does your wife have a reminder and you do not? If so, are you including reminders in your budget?
".It reflects as a negative number in Budgets for future months"
To be clear, with budget set to show "details", are these negative number showing under the heading "budget", "actual", or "balance"?
Under budget actions, is View set to include reminders?
Have you tried validating your file under file operations? Unfortunately there have been problems with budgets though they typically involved disappearances of an entire budget.
Clearly both your and your spouses reminders should be working the same way. If you delete the spouse reminder. Do the future actuals go to zero?
It seems as if the reminder "thinks" it is a negative expense rather than income.
Maybe others will stop by; I am out of ideas
Good! so create a new category: say, SSI-SPOUSE . assign it tax line to same as original spouse category and then try using that.