I have changed a setting in my antivirus (Kaspersky) under the Anti-Hacker settings from Maximum Compatibility to Maximum Speed, when doing a download test Here and on speedtest.net the results are great. Have I broken something?

I cleared the cache before each test the ones that are low is where I have changed the setting back to maximum compatibility.
Mon, 9 Jul 2007 19:06:09 UTC
1st 512K took 31 ms = 16516.1 KB/sec, approx 136093 Kbps, 132.9 Mbps
2nd 512K took 1610 ms = 318 KB/sec, approx 2620 Kbps, 2.56 Mbps
3rd 512K took 18500 ms = 27.7 KB/sec, approx 228 Kbps, 0.22 Mbps
4th 512K took 20781 ms = 24.6 KB/sec, approx 203 Kbps, 0.2 Mbps
Overall Average Speed = approx 34786 Kbps, 33.97 Mbps
These results appear to be rather fast - this page was possibly in the browser cache.
To repeat this test from the source server click here.
Mon, 9 Jul 2007 19:09:56 UTC
1st 512K took 16 ms = 32000 KB/sec, approx 263680 Kbps, 257.5 Mbps
2nd 512K took 62 ms = 8258.1 KB/sec, approx 68047 Kbps, 66.45 Mbps
3rd 512K took 141 ms = 3631.2 KB/sec, approx 29921 Kbps, 29.22 Mbps
4th 512K took 78 ms = 6564.1 KB/sec, approx 54088 Kbps, 52.82 Mbps
Overall Average Speed = approx 103934 Kbps, 101.5 Mbps
These results appear to be rather fast - this page was possibly in the browser cache.
To repeat this test from the source server click here.