And make sure you're using the newest version of taig too
Yes, I have this problem on my 5th gen iPod Touch 64Gb. Normally, around 75Mb was being used for 'Documents and Data'. After the Taig jailbreak it's 500Mb.
Although 'Other' has been reduced by a similar amount, so swings and roundabouts!
Anyone else getting below average battery life? I lose 25% within 2 hours.