You problably have this problem, "or not", but is normal having problem accessing Sharepoint and Microsoft CRM, you have all configurations right on server and allways works fine there, some computers can access sharepoint or Microsoft CRM, other dont, but you say to youself "There all the same, whats wrong", well sometimes litle things can be like a mosquito.
This problem can be a simple thing like Changing and adding line on "Host" File.
This file is located on your PC "C:\WINDOWS\system32\drivers\etc" if you have Windows XP.
Have to open "Host" file and add a mapped address adding IP and server name
10.0.0.10 crm:5555 crm.contoso.com:5555
10.0.0.10 Sharepoint.contoso.com crm.contoso.com
Try again and you problaby will get access.
Remember this could be only one of the problem, "proxys", network problem, DHCP, there other issues, but now only focus this.
Hope this article help.