BB gone very slow ...help please

Question

I live in a rural area, am about 3 miles from the exchange, so I'm used to not having a fast service, however my speed often runs around 1.22Mb/s download and 0.38Mb/s upload. But yesterday it dropped to very slow. I just decided to leave it for 24 hours to see if it sorted itself out. Well it didn't and I'm here now looking for some help please!
I have checked my local exchange, no problems reported.
I have worked through the BT BB Speed Wizard thing.
I did the Speedtester and these are the results
FAQ
Test1 comprises of Best Effort Test: -provides background information.
Download  Speed
107 Kbps
0 Kbps
250 Kbps
Max Achievable Speed
 Download speedachieved during the test was - 107 Kbps
 For your connection, the acceptable range of speeds is 50-250 Kbps.
 Additional Information:
 Your DSL Connection Rate :1600 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
 IP Profile for your line is - 135 Kbps
If you wish to discuss these results please contact your ISP.
If you are experiencing problems with specific applications, servers or websites please contact your ISP for assistance.
Your test has completed please close this window to exit the performance tester.
I've changed all the filters and I reset the Home Hub a couple of hours ago. Nothing...
THis is the info from my Home Hub:
ADSL line status
Connection Information
Line state
Connected
Connection time
0 days, 03:49:10
Downstream
1,600 Kbps
Upstream
448 Kbps
ADSL Settings
VPI/VCI
0/38
Type
PPPoA
Modulation
G.992.1 Annex A
Latency type
Interleaved
Noise margin (Down/Up)
7.3 dB / 19.0 dB
Line attenuation (Down/Up)
62.9 dB / 31.5 dB
Output power (Down/Up)
2.5 dBm / 1.5 dBm
Loss of Framing (Local/Remote)
0 / 0
Loss of Signal (Local/Remote)
0 / 0
Loss of Power (Local/Remote)
0 / 0
FEC Errors (Down/Up)
245 / 7
CRC Errors (Down/Up)
324 / 11
HEC Errors (Down/Up)
4266 / 39
Error Seconds (Local/Remote)
23 / 7

Answer 1

Noticed it was back to normal speed again just now, so I did another speed test.
Results
Test1 comprises of Best Effort Test: -provides background information.
Download  Speed
1130 Kbps
0 Kbps
2000 Kbps
Max Achievable Speed
 Download speedachieved during the test was - 1130 Kbps
 For your connection, the acceptable range of speeds is 400-2000 Kbps.
 Additional Information:
 Your DSL Connection Rate :1600 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
 IP Profile for your line is - 1250 Kbps
Obviously I'm pleased that it's back to normal but confused as to what caused the problem - 24 hours of extremely slow connection and then it's normal again. ANy ideas?