I found this walkcycle somewhere and cut it up in ToonBoom. 9 frames then back again for 9 frames.
It's not perfect and the feet need some work by you to be exactly on the line. I think frame 9/10 might be doublers too.
Images zip:
http://rapidshare.com/files/376686725/anim.zip.html
Backup: http://www.sendspace.com/file/d1u8ax
ToonBoom file:
http://rapidshare.com/files/376683859/TB_Walkcycle.zip.html
Backup: http://www.sendspace.com/file/au8r04