Cydia's not working on 4.2.1

[thunderburns]

Hi, I had a problem with my iphone 4 and upgraded to 4.2.1(now regretting it). I used redsnow to jailbreak and install cydia but when I try to open cydia, it just won't open. Also, the cydia icon is white.

Can somebody tell me if there's a way to fix this?

[Poseidon79]

Run redsn0w again using the "just boot tethered" option. You will have to do this each and every time the phone reboots... so you'll have to do it after Cydia updates... again after winterboard installs..