My router is fine... Unless the power goes out in the house. For some reason, it changes all the IP addresses, so BOINCTASKS requires that I reconfigure every computer for the new IP address. and the BoincTasks master has to have every computers new IP address set also, as well, as FAHControl.
So I know what you mean about router issues.
This is not a router issue- but a configuration issue. Your user requirement is "static IP address for each client". In order to achieve this, you have several options.
Go to each client and configure the wired/wireless connection you're using for static IP address by specifying the IP address, subnet mask and gateway address. This is a bit heavy on the maintenance side, but still works should the DHCP service fail on your router. Make sure to only use IP addresses outside the DHCP's assigned address range to avoid duplicate assignments (but still within your net/subnet of course).
OR
Go to your router and configure your DHCP service (assuming you have the DHCP service running on the router and not on a separate device). Enter a static lease for each client (i.e. tying its MAC address to the IP address you'd like it to use). Again, make sure to only use IP addresses outside the DHCP's assigned address range to avoid duplicate assignments (but still within your net/subnet).
If you have a "cheap" consumer router, then you might only have a function to "remember" each client's IP address (has most likely to be activated for each client separately).
Edit: Although the first approach is more resilient, I actually prefer the second. That way I can make all changes in a central location. To make sure the DHCP service is always running, there is a "watchdog" that monitors all essential services and restarts them if necessary. (This is on pfSense, running on a Supermicro E200-9A with 16GB ECC RAM and a 256GB Intel SSD)