Newbie needs help (again!)

Newbie needs help (again!)

I'm embarrassed to keep showing up in the forum asking for help, but you people have been so great! 

I'm currently using a fairly simple form on my website to collect basic data and send an email reply.  It seems to work correctly about 60% of the time, but several people have encountered "Please Wait" screens that seem to "freeze" their computers.  I haven't been able to replicate this problem, and I'm only going on anecodotal reports, so i don't know if users' computers are actually frozen, but still it's causing problems that amount to negative PR for my group. 

The users who report problems operate both Mac's and PC's, and appear to be using either Firefox or IE.  My tests on a my Mac, using Firefox or Safari, yield no issues what-so-ever. 

Has anyone run into this problem with forms before, and if so do you have any suggestions?  Do I need to be logged-in to my Zoho account for the form I set up to work properly?  Or perhaps should I be logged out?  Does that even matter? 

Thanks in advance for your support! 

John