WCR-GN in bridge mode, potential setting crash with TP-LINK router?

[VoidGenome]

Hi I am having a weird and serious problem here. I have a TP-LINK router (WR841N) in the center of my home intranet and a WCR-GN in my room as a bridge. Due to some cable issues we are not able to connect to the Internet via LAN cable at this moment so our Internet provider gave us a USB dongle as an alternative. The dongle is connected to a Windows Vista, and in turn connected to the LAN port of TP-LINK router so that the Internet can be shared throughout the intranet.

From the TP-LINK router there is a LAN connection to my WCR-GN, which is then connected to my computer via LAN cable and at the same time supporting my smartphones with wireless connection (supposed). Problem is, I cannot access my WCR-GN via this set up. The DIAG light is on when the LAN cable from the TP-LINK router is plugged in. The Internet connection is there, just not stable. Wireless connection is completely dead. The strange thing is, when I unplug that cable, everything just comes back on. DIAG light turns off, wireless broadcast restarts, and I can access the WCR-GN without any problem. I have also tried connecting the LAN cable directly to my computer but in that case, my computer cannot connect to the Internet.

I am completely baffled and would really like some answers on this problem. I can provide screenshots or whatever information needed. Thanks