If this question crosses your mind in regards to an issue, you need to disclose it. The seller must disclose any and all known defects and problems with the home. The buyer can (and sometimes does) litigate over issues that were known to seller but were not disclosed on property disclosure forms.
Failing to disclose now, can lead to a variety of problems later. Once the home is under contract, in most cases the buyer will have a home inspection. If the home inspector finds something that should have been disclosed, the buyer will either walk away from the sale or ask for a price reduction. If the inspector misses the issue, and the buyer can pursue court action against the inspector and seller. However, if the seller disclosed the problems, the buyer is aware of the issues prior to making an offer; said buyer is less likely to walk away from the purchase and cannot ask for a price reduction because the issues were known at time of writing an offer.