Turbocharged to Poor in secs!

[WarrenPeace333]

Greetings,

Searched the forums, have only found some vaguely similar probs, but not exact. Have been using LW on my G4 PB for 9 month with no major probs until now. Never had too post B4 so apologies if I ramble on before I ask my Q.

I only seem to be getting a stable connection at certain times of the day. If I connect between 02:00 - 15:00(GMT), I am Turbocharged and able to get resonably fast DL speeds. But if I connect or am still connected outside of these hours the quality bar seems to go a bit "Schizophrenic". The bar drops down to 1 for a few secs saying poor and then shoots back up to Excellent/Turbocharged for a while and then once again it drops. When I check the Monitor, I can see Ultrapeers droping out and new ones connecting rapidly. This activity coincides with my bars fluctuating, T'charged with 5 Ultrapeers connected and Poor with only 1 or 2 U'peers on.
This is all very nu and weird to me. Before this month LW seemed to work quite well at anytime of the day, better speeds at night etc, but never this unstable. So my question "Is this a problem on my end, that I can resolve (ISPblocking,prefs,ports etc.) or are others having this problem too?"

Info:
OS X 10.3.9
Nortons Personal FW
512 MB RAM
40 Gb
1 MB Broadband (TalkTalk)
Netgear DG834G
Home
LW Pro 4.8.1(if it ain't broke...) Java 1.4.2.09

Hope someone can help me out.
Cheers,
W'n'P333