Lotus Sametime Client version 7.5.0

Hi, I am new in the Lotus Sametime. I am facing the problem in that.I have 7.5.1 client version of sametime. on every machine in the startup its taking to much time. can anybody tell me why its takes time. Somebody told me that there is one more version of Lotus Sametime is 7.5.0 and I check on internet but i didnt get this version. can anybody help to you download the sametime client version 7.5.0.