apparently,it seems i am connected but wen i try to download a song, the following message pops up:
LimeWire is currently connecting to the network.Your search may not return many results until you are fully connected to the network.

Also, in Tools>Options>iTunes>Sharing, i can't seem to check the box "Share my music" for some reason.I've checked the compatibility mode but nothing happens.so if someone out there knows this stuff and can help me out, i would really appreaciate it.

Tools>Options>iTunes>Sharing & press the Add button. Then direct it to your folder you wish to share. Select it & press the Open button. Then press the Apply button.
Another way to do it is to go to LW's Library window & then to the menu File>Add Folder to share.

For your other issue please supply the following information:
1. OS version? (eg: Windows 98)
2. What firewalls you have?
3. ram?
4. HDD space available?
5. Connection type? (eg: dial up, cable, broadband, etc)
6. Modem & router brand name & model numbers?
7. Where are you trying to connect from (home, school, work, etc.)?
8. Which version of LW & Java you have. You can find out by going to LW's menu Help>About LW...