This type of situation occurs frequently -- usually because
YouTube has shut down many of its servers without telling
anybody. (They do this often in order to do stupid things like
-- change their Inbox system back-and-forth every few days;
-- remove all their blog comments, only to put them back;
-- upgrade their look, even if it turns out to be a downgrade;
-- make sure that your "reply" to someone's video comment
always appears as a "new comment".)
If YouTube is slow or stuck, and you get messages or advice
to change things, DON'T. It's never a good idea to tamper
around with things you may not be knowledgable about or
comfortable with -- such as java scripts, firewall settings,
flash players, antivirus utilities, pop-up blockers, registries,
or even different kinds of browsers -- because absolutely
none of those things are going to help you in the end.
Your computer/YouTube was working fine before, right?
The first and best option should always be to try and work
with what you already have -- rather than disabling, erasing,
uninstalling, separating, altering, downloading, installing,
or changing things (which may make things worse for you).
The problem of slow or stuck video downloading or buffering
often corrects itself within a few hours or by the next day.
If it doesn't, then there may be a problem with your "cache",
particularly if you got "java script" or "flash player" messages.
(That's why channel pages may sometimes appear normal,
but not regular video pages.)
Whenever YouTube seems stuck or displays weird things,
I always empty my cache of all "temporary internet files",
"cookies" and "history". Things are usually okay afterwards.
If you're not quite sure how to do this, or if you want several
other tips on how to make YouTube run faster (all without
having to change anything), then please click my avatar
and email me. I will lead you through everything in simple
English with easy and understandable "baby steps".