Router/Firewall downstream problem

[t3d]

This may be similar to chrissy2k6's post, but I don't know whether it is the router or the firewall that is curbing my connection speed.

I had a Netgear RangeMax 108 MiMo router which refused to keep a wireless connection up for longer than a second. The wired connection was decent though and gave me all of the 6Mb download that I get from my ISP.

I've just bought a 3com OfficeConnect (model 3CRWDR101A-75) which seems to give a decent wireless connection but all the online speedtests I have used give me around 130kpbs download speed! Web browsing etc is noticably slower.

The router firmware interface reports:
Actual Data Rate
Up Stream 448 (Kbps.)
Down Stream 6592 (Kbps.)

Operation Data Upstream Downstream
Noise Margin 24 dB 12 dB
Attenuation 31 dB 30 dB

Defect Indication
Indicator Name Near End Indicator Far End Indicator
Fast Path FEC Correction 0 0
Interleaved Path FEC Correction 136 846
Fast Path CRC Error 0 0
Interleaved Path CRC Error 1 0
Loss of Signal Defect 0 ---
Fast Path HEC Error 0 0
Interleaved Path HEC Error 68 0

So the router knows the downstream rate is around 6mbps, but it won't give me a connection at that speed! Anyone got any experience with these routers or suggestions to try to fix it?
Cheers