I just want to say I really appreciate all the help and advice you've been giving me, so thanks everyone!
@GRUNTERSDAD - I actually replaced the bearings that came with the pedals shortly after recieving them as they were'nt up to scratch. =) The slave pedal by itself works fine, I still need to adjust my spring tensions a little in order to get it to match the master but this won't take much doing.
@bud7h4 - I've actually just invested in a new drive shaft now, this one:
Including postage (I've had to pay for speedy delivery) it's actually ended up costing the same as the pedals. =P I hope this one is good enough, third times the charm right?
@MrInsanePolack - I can confirm that the drive shaft is worn out. I am able to move the beater about 10mm. I did recieve my new drive shaft through the post yesterday (Not the one linked above) which I bought from Ebay for £27, but the same thing is occuring with that one. I would have thought that £27 would have been enough for a decent drive shaft, but I guess not. This is why I've spent £45 on a Stagg one, which I hope will fare better. I won't be recieving this until Friday at the earliest, so I won't be able to say whether it has made a difference until them im afraid. =(