D-Link DP-300U (DHDP300U) Print Server "hp 1020 test without" Questions

...HP LJ 1020 Hi... I have a D-Link DP-300u as a LAN print server and HP LJ 1020 (USB) plus Epson LQ2180 (LPT1) connected to it. At first i can print without any problem to both printers. But next day i ...