Nokia 5110 checksums

Hi every1,
I have this little problemo. See, I modify a flash file using ppmedit (or ppm manager), flash it back to the phone and the phone says "contact service". The funny thing is that when graphic or fonts are changed averything looks, OK, after updating faid phone works normaly, but when I try to modify the tone or text chunks phone says contact service. I checked the phone with wintesla and wintesla shows that PPM checksum test failed. How (or what software should I use) to fix 'em checksums.
Thnx

try to use chkfixer by joox.

it works for me!:)

hope this helps!

Or PPM Manager, it's in the download section.
Open the fls file, and then from the 'Tools' menu click on 'Update all PPM CRC's, save the file and reflash to phone..

PPM manager didn't fix the problem. Neither did rolis flasher (scan chk or something like that). Any more ideas?

...and neither did NFree 1.2. Phone still says contact service and I dunno what to do :(
The funny thing is that "contact service" appears only after editing the text chunk (with PPMEdit or PPM manager) and the menu pictures (Only with FGraphic. With PPMEdit all is ok). Maybie the text chunk is a few bits too long? I added some new text symbols in order to use them in writing sms messages. But then why is it ok in pawaka's fls file with 60 ringtones? Beleive me, this is pretty weird :/
Please help me if u can.
Bye.