Is there any difference…?

Is there any difference between Small Business Server 4.5 vs. Proxy 2.0, Exchange 5.5?

In one office SBS 4.5 and no issues with software or surfing and booking on certain websites.

In the other office Proxy 2.0 sp1, Exchange 5.5 (sp4) and NtServer 4.0 (sp6a), issues with “Office Email Merge v.150” and booking on “NetFaresOnline.com” website.

I did not set up the second office using the stand alone’s, could this just be a bad setup and config. on the stand alone software, or does nayoneknow of any differences between these 2 products?