Just to add I am also facing the same problem when I upgraded to lime wire 4.10 the speed has taken a big hit. I also post a thread(please look at thread Speed Issues version 4.10.5) and tried the same steps given here. No good. I like my good old limewire.

I have uninstalled the new version and my speeds dont drop like they used to on 4.10. The fluctualtion in speed is also less. If you want to revert back to the old version of limewire simply search for lime wire in limewire itself and you may find someone with the old copy of lime wire.

Try upgrading java from
http://www.java.com/en/download/
I also realised i am using a very old version of java. This might help.

Can anyone also help how much is the maximum download speed I can get using limewire? If it depends on speed of Host's i am connected to then if I get Limewire Pro then would I be able to connect to a maximum of how many hosts ?? at present I can connect to max of 8 Hosts.

If I have enabled uploads would it affect my download speed?

OR IF i disable my uploads what would happen? Hope someone can answer this I have more to ask