Clarke CEW1000 impact wrench - feedback (mine's useless!)

[oooOLLIooo]

Hi all

I have just bought a Clarke Impact Wrench CEW1000 (mains powered), but despite the generally very good reviews on the net, i am not impressed: it won't undo my wheel nuts, torqued at 140 Nm. Well, it will if i have just torqued them up, but it won't if they were torqued up only a few weeks ago (slight corrosion making them tighter I guess). Having no issue undoing them manually, so they are definitely not stupidly tight.

The thing is supposed to deliver 450Nm!!
Has anyone got one?
I would welcome some feedback before I try either an exchange, or just to buy something else...

Many thanks
[IMG:480:480]http://i1222.photobucket.com/albums/dd487/ooollliii/090003aef125184c7ea1958e19496cad_zpszrd8niir.jpg[/img]

[oooOLLIooo]

Thanks guys, i wasn't expecting miracles for the price, but i thought it should be up for this job!