DVI Splitter and/or DVI to HDMI Cable Resolution Problems

Hey guys, so I bought a dvi splitter recently, along with a DVI to HDMI cable, so that I can copy my monitor display to my TV. The splitter works fine when only the DVI connected to the monitor is plugged in, but when I have both the monitor's DVI cable and the DVI to HDMI cable from the TV plugged in, the resolution gets really messed up (something like 600 x 400, or around there). When I try to fix the resolution, it won't allow it. Is the problem that my graphics card isn't powerful enough, or my TV and/or monitor are setting limitations, or something else?




Tech Support Guy System Info Utility version 1.0.0.1
OS Version: Microsoft Windows 7 Home Premium , Service Pack 1, 64 bit
Processor: AMD Phenom(tm) II X4 965 Processor, AMD64 Family 16 Model 4 Stepping 3
Processor Count: 4
RAM: 4095 Mb
Graphics Card: AMD Radeon HD 6670, 1024 Mb
Hard Drives: C: Total - 953766 MB, Free - 423871 MB;
Motherboard: ASUSTeK Computer INC., M4N68T-M-V2, Rev X.0x, MT7015K17101832
Antivirus: Microsoft Security Essentials, Updated and Enabled