NKTA:
I know that bug. The reason I haven't corrected it, is that we cannot apply patches to DB2020 CID49 phones. First you need to upgrade the EROM CID to 52 using XS++. Connect your phone to XS++, and when it ask if you want to upgrade your CID, then press YES. DO NOT use SEUS(Sony Ericsson Update Service), because it will update your CID to 53, and we don't want this. Then download a K610 CID52 MAIN, and try again. It is recommended to use the same MAIN what you have in phone, but you can use newer versions of K610 MAIN as well(it will work, I'm sure).

ahmeer:
You need to upload a custom pack. In XS++ 2.x Guide read the III. Region Codes and CDA/Custpack. In step IV. skip the (do not select any) MAIN or FS. Upload the custom pack only.

kendo2748:
You can use XS++ or SETool2 Lite as well. It is just a matter of taste. Here are some tutorials: XS++ 2.x Guide, Flash your phone using SETool 2 Lite. No matter what tool you use, select JUST the MAIN. At this time you no need to flash the FS nor the custom pack.