Not really sure, sorry! Do you know anyone else with the exact same phone who is using the same app? If not, then it could be a problem specific to the phone's firmware. If that's the case, I'm not sure what else you can do, besides what you've already done (i.e., let the phone manufacturer know about the problem). Reinstalling the firmware is a possibility, but this isn't always that easy, if the manufacturer doesn't provide a software installation/repair tool that you can use. You'd otherwise have to look into rooting the phone and re-flashing the stock ROM (and I'm afraid I wouldn't be of any help there -- you could check the forums at XDA-developers.com to see if anyone there has experience).