Just had a situation where after resume from standby, the CPU (AMD 7840U) was stuck in a very low-speed state (0.5 GHz) rendering the system extremely sluggish. A reboot resolved the issue but seems indicative of a driver/firmware/BIOS issue.
I have seen this on my 7640U using linux with the old BIOS 3.02 but not since the upgrade to BIOS 3.03. Are you on the current BIOS version?