Hi tasha I too had the same problems... The wifi hotspot would work but when people tried to access the internet (web pages) nothing would connect. I had similar issues with my HTC Desire and found this solution which also worked on my Sensation XE:
found this on another part of the andriod forum, tried and it works a dream.
* note this only works for branded Desires on Orange.
Menu/settings/Wireless&Networks/Mobile networks/Access Point Names
You should see the following three APNs;
Orange Internet
Consumer Broadband
Orange MMS
Select Consumer Broadband
CHANGE the APN from consumerbroadband to orangeinternet
CHANGE the Username from <Not> to Orange
CHANGE the password from <Not> to Multimedia
Make sure you use the capital first letters exactly as I've typed them there.
Authentication type should be set to CHAP.
Press your Menu button, tap "Save"
after this both wifi hotspot and usb tethering should work.
Enjoy. I know it says this only works on Orange Branded Desire's but ignore that as It has worked for many people on different handsets.
(hit the thank button please heh)