Help... PSU/MOBO question

I have a Dell 8250 with its original PSU at 250W and its original motherboard. If i upgrade the PSU to a 350W will that create any problems such as overpowering the motherboard or anything of that nature? I talked to a dell representative via chatroom and he said, I cannot b/c the motherboard will not handle it. Is this true? or can i indeed upgrade to the 350W and not do any damage to the system?

I have a system that is almost identical to yours.

Dell 8250
P4 @ 2.4Ghz
768 Mb Pc 1066

I had a enermax noisetaker 470w psu, that I purchased for a build that never hapened. To make a long story short, this psu is now in my 8250. No adapters needed.

The one thing that you will have to consider is that, there is not a hole in the back of your dell case for the power switch on an atx psu. But a dremel will fix that.

Someone pointed out on the other thread that Pc power and cooling makes psus that are compatible with dell systems. That may be your best option.

But I have to call BS on the statement that the MB won't handle a bigger psu.