mmm i use to have the same prob (and the only way i found at the time was format 🙁 ) and they arent related to the yahoo messenger so dont bother with reinstall it, well what i did to solve this was to search myself for the spyware files, they are usually (i think like 99% of the times) installed on the windows and windows/system32 folders, (besides the internet temporal files, you can delete the whole content of it and there isnt any prob) just organize the windows and windows/system32 folders to view the most recently files, i check often the files there and when i see a new file and i havent installed any software or hadware recently, i just delete them (but make sure if itsn not a windows file, check the file properties and see the license, vendor and all of that stuff, spyware normally dont have any of those) or see if in spybot apears the names of the file. ok if you delete them with spybot and they apear again, then you need to identify the spyware files, you need to delete them manually, but the system wont allow it, so first try to delte them runing windows in safe mode, if you still can this way then you need to use another partition (lets say for example that the c is infected, the use the d partition and enter the c windows folder from there) there is another way of delete the files if you dont have a partition, but try first those 2 options.
i hope i explained myself (sorry my english is not to good) try what i said, if you have a question i will be glad to help, good luck.

i just get yahoo plus, and its great, i was searching for a prog to change chat servers, but where i can get help for this prog? i still dont get how tho change my default emoticons and use another countries….

yes, i have seen this happenig and i tryed myself and this only ocurred to me when i use yahelite, i dont think this happen with ymsn.