Duplicate titles got me stumped

[SamCUK]

Webmaster tools is showing duplicate titles for example:

http://www.musicliveuk.com/lincolnshire/bands-in-lincolnshire/

and:

http://www.musicliveuk.com/lincolnshire%20/bands-in-lincolnshire/

What's the %20 all about? I didn't create that page and it is a duplicate of the first. I'm also getting them for some pages with capitialisation? Eg:

http://www.musicliveuk.com/lincolnshire/bands-in-lincolnshire/

http://www.musicliveuk.com/Lincolnshire/bands-in-lincolnshire/

I have also installed buddypress on another site I work on (I use wordpress) and have since had duplicate title issues for members that have signed up:

/members/admin/activity/friends/

/members/admin/activity/groups/

/members/admin/activity/just-me/

These pages are all showing duplicate titles? How can I fix this?

I use all in one SEO pack and have <a title="Click for Help!">Canonical URLs checked.</a>

Any help much appreciated!

[SamCUK]

FYI the urls shown above are just examples and not actual URL's.