Sounds like the USB extension may not be up to spec if it either not supplying enough power or the voltage loss along the run is such that the data signals (D+/-) are marginal.
But yes I would consider that unusual for a short extension (up to 1m).
The wiki explains that although the standards allow for extension cables up to 5m in length depending on the quality of the cable they can be out of spec rather shorter than that.
For longer distances you have to use an active cable which is basically a powered single-port hub on the end within 5m such that you can daisy chain these together, or other methods involving conversion (e.g. USB over CAT 5), but they are more expensive.
prompt $P - Invalid drive specification - Abort, Retry, Fail? $G
prlzx on iDNET: ADSL2+ / 21CN at ~4Mbps / 700kbps with IP4/6