Funding Revaluation Reduces Funding

We have been running the funding revaluation process on our multi-currency projects.  Usually this increases funding, but sometimes, it attempts to decrease funding.  The problem is, when it tries to decrease funding, we cannot baseline the budget because we have accrued revenue over the new funding amount.  For example:  Say, original funding is 11,000 and accrured revenue is 10,000.  The revaluate funding process reduces funding by 1,500 (to 9,500).  We cannot baseline this amount because revenue exceeds the amount we are trying to baseline.  This doesn't seem right and basically makes it so we can only run the revaluation process