javascript error on JoomDonation config page

The configuration page worked for a while, but now throws a javascript error. I have pasted the error below. This error is preventing anything in the configuration settings to be changed.

uncaught exception: [Exception... "String contains an invalid character" code: "5"

any help would be greatly appreciated.
I am running joomla 1.5 and the latest version of joom donation. The error occurs in IE and FF.

Thanks,
matt

Hi matt

I am sorry for lately response. Busy prepare for my wedding these days.

Regarding the issue you are having, could you please :

1. Upgrade your site to latest version of Joomla 1.5 (Joomla 1.5.25) .

2. Upgrade your site to latest version of Joom Donation (version 2.9.0)

If the issue still happens, please submit a support ticket giving me administrator and FTP account of your site so that I can check it. It seems none of my customers get the same issue before !

Tuan