Cracking filler in gaps of poorly manufactured floor

Q: Our house has dark Brazilian Mahogany hardwood floors. Unbeknownst to me, last year, at the time of purchase, the floors ranged anywhere from 4 1/2 inches wide to 4 2/8 inches wide. Where the boards don’t match up, some kind of gap filler was used. However, over the course of the last year, the filler has been falling out of the gaps, leaving unsightly gaps in the boards, sometimes as wide as 2/8 of an inch.

This has occurred particularly in the higher traffic areas, but it is occurring all over the main floor of the house. In addition, where the filler has not fallen out it has cracked, leaving zig-zag looking patterns in the filler. I am at a loss. Is there a product that can fill the gaps that have lost their filler? Will it prevent this problem in the future? Is it something that I can do?

A: Sounds like a poorly manufactured floor. There are 2 products you can look at. Timbermate makes great claims for their filler: Another product I like is called, I think, Colorrite, which comes in tubes with hundreds of colours to choose from. It is more like a caulking.